Depends on what country you play as really.

how did you play.. did you get too aggressive and spread out? Would think tanks; AA and strike fighters would be a decent mix for Russia. But sounds like you may have gone on offensive too soon till ready?? There was some Russia threads with specifics. But if go nuts in a direction Russia so spread out leaves you exposed so may be tactics over troop types.

Some other coutries depends on what fits country.. ie island (aussi; cuba; ireland ; UK; etc) a strong navy is a must. If in open terrain probably Tanks or AFV good. I personally do a mix of Land; Air and Sea. Main change factor to me is Strike Fighters but I dont go blasting troops ahead of what I can cover.

Main thing if getting steam rolled generally happens to people who pick big fights early then after both countries dinged up a third country comes in and steam rolls you. so attack what you can beat steadily make sure keep fronts defended. see people have giant stack in moscow... like wtf push them to edges .... if people get all the way to moscow the game already over.

Pick troop types that work for you and better to have a few highly researched types than way too many multi tier. AA units early on not going to pay off as most dont have strong Airforce for awhile.

How / what types of troops steamrolled you?

737373's not blowing you off; it really does depend on the specific country in a lot of cases. Many/most come with a unique set of circumstances. That being said, one thing you might want to check out is the military doctrine that country uses. That's going to tell you where your default bonuses/advantages are for that country. Now, that doesn't necessarily mean those are all the best units for that country, but it's a decent enough place to start. Next you might want to consider geography, terrain, etc.

In short, I'd say let the COUNTRY dictate to YOU what your unit selection and strategy will be, rather than the other way around. If you do at some point have your heart set on using a particular combination of units, though, I'd say make sure that you pick a country for which those units are best suited.

So my earlier post was made when I didn’t have much time so I could only do a one-liner. But now that I have a bit more time to spare I can actually make a more detailed post on my strategy. (Note: I wanted to edit my post but I think I’d rather you get notified by this )

I usually play island nations, as I don’t often want to engage with enemies and instead want to stay alive as long as possible. As such, I usually play Australia, New Zealand and Ireland. I do experiment with different countries occasionally, but so far none have really suited me.

I always research my ‘basic four’: Motorized/Mechanized Infantry, Armored Fighting Vehicles, Air Superiority Fighter and Corvettes/Destroyers. I used to research Mechanized, but I realized that Motorized is more defensive and suits my play style better. AFVs are all-rounders that do well against most ground units while being cheaper than Tanks and fare better on most territory too ASF is for air superiority in my territory. Corvettes secure my coastal cities, and I usually follow it up with Destroyers, as powerful ships capable of sinking convoys and other ships easily. Sometimes I research Frigates if I find that ASFs aren’t enough: sometimes I jump straight to Destroyers if the country is too big, like Australia.

For island nations, I like to simply go defensive and negotiate until I’m safe; in fact, I dislike attacking, and will only attack if I’m attacked first. Once I’m in a coalition, I may start to Attack countries if I’m reassured I’ll be supported if I start to lose.

Going back to what I research, what I research next depends on what I’m playing. Different types of Infantry depends on what country I’m playing. Countries consisting of multiple islands, I’ll do Naval Infantry and do away with Mechanized. Airborne is a nice option, but I generally prefer to build up a stronger assault force before I create airborne Infantry.
Tanks are another option once I’ve built up a strong army; providing even more firepower.
Helicopters are a additional tool I sometimes use once I’ve cleared enemy ASFs, helping to mow down Infantry, with Strike Fighters. Naval versions combined Aircraft Carriers and 5 destroyers to make a carrier strike group are usually used once my empire is big enough, allowing me to extend my range to hit countries in other continents.
I generally don’t bother with Submarines; my Destroyers are good enough for ship-to-ship Combat.
I find Missiles a waste of resources most of the time; dedicating a city of producing warheads is pointless to me, as it takes up crucial mobilization space which could be used for other forces (also; my other coalition members usually create missiles anyway )
I’m too low a rank for officers teehee

this is not the worst mix for russia but u need national guards to get max defense possible also u can replace aa with asfs they all need lvl 1 airport and will allow ur units to fly every where

start with navy to avoid early usa invasions get frigates first ( u might build 1 or 2 covve if necessary but if u can afford not to don't). I'm not sure why u don't like marine but I think they are good to attack usa later ( if not being an ally) the 50% bonus IS good.if u can find ally on the other part of thhe world u can go for air mobile but else who will they find air fields to operate? u can go for both. Strike fighters ? idk I think asfs are more suitable

Navy marines dont suck just certain purpose .. good at attack and surprise entries not in cities/ports ...really bad at defense but in general I only use if playing in pacific as a lot of islands or on special maps with island Victory sites that a lot are on islands with no ports. But in straight map not worth cost of resources/bases as require navy and army 2 plus something else to build.

Strike fighters are good and for cuba maybe even choppers for defense. definitely need stronhg navy ; 1st for defense but then to lead invasions. What map is it? I usually just stick moterized as get lvl 6 basically build in artillery. with specialized troops (marines; Airborne; spec ops) you really need to pay attention to what they do best where and dont expect to use as general infantry

just with Cuba build defense first .. pay attention who in area may be vulnerable (ie if USA battle Canada up north hit miami) or Mexico and USA fighting hit Yucatan peninsula) then attack in mass at a closest point get foothold ; have friggets provide Anti air to protect from planes. get a Airfield asap in new country so can fly in reinforcements as waiting to sail reinforcements wont last long. If no openings for invasions just go after the smaller AI island countries in Caribbean but dont over commit.

Best bet try to get ally in USA or Mexico maybe Venezuela think closets S American. then go after the ones you dont ally with. But will need friends in at least one direction or hard to defend north; west; south.

And I no alot dont agree but i prefer more friggs over fewer Destroyers as much more versatile and less requirments to build. If get enough resources a Naval officer / 4 frigg stack makes a very good unit. I beaten Destroyers and Cruisers with my friggates and yes will lose 1 or 2 but than replace with the other units as you will have higher # than destroyers. plus a few friggs will provide air cover for whole island. 2 friggs will take down 1 destroyer heads up.

btw sams cover all cuba so they are ur best air defense unit. choppers won't get to you anyway.

if u r active don't attack with the frigates use them to block any coming invaders

if u r active and will keep ur asf scanning sea routes yes u can leave minimal defenses (1 motorized + 1 ng in cities) and the frigtes to blockade

hmmm if u r super active yes but u need to block any string stacks. idk but 1 motorized is not of great help he is defeated by almost any other stack

Honestly, Cuba's Eastern doctrine is definitely for ASF, corv, and frig, possibly with destroyer along with UAV due to the updates. Pop in some gunships eventually and you're good to go for the most part. Strikes are decent everywhere, although they are definitely excellent in European doctrine. Hence:

1. Air: ASF, UAV, Gunships
   
2. Sea: Corvettes, Frigates, Destroyers
   
3. Land: Motorized/Nat Guard, Marines, Airborne, Special Forces, Tanks, Tank Destroyers, SAMs, Mob. Arty/MRLS, Radar
   

Generally; adjust as necessary for specific circumstances. In your case, I would have started with heavy ASFs, sprinkled in some UAV and Gunship, gotten corvettes and ngs mobilizing early, adding in some marines and airborne, then tank destroyers and radar, then marines, airborne, or sf with some radar added and them some artillery.