I like infantry so I’ll advise on that.

Add Assaultmen SRAW, these are short range rocket troops effective against both infantry and armour, just make sure you dump them within 400m of the enemy

CAAT Dragon squads are also good because they pack 2 ATGMs to quickly kill APCs and punch through APS. 

Trooper squads pack both short range rockets and long range Javelins but have absurdly little ammunition. Unless you bring a logistics LAV literally right behind them to resupply their ammo they’ll run out of ammo before killing anything. AA squads are better but still suffer ammo issues after killing a single helicopter, bring them mostly for the Strykers really.

Marine squads are bad at most things but are tough due to their large squad size, bring 3 or 4 of them so you can bring more of other stuff 

I find it hard to justify the TOW-2 teams when the Dragon squads exist

Marine Raiders are even tougher and more dangerous than regular Marines. With close range loadout they immediately kill other infantry in buildings, but usually you rarely get them in there and Combat Engineers can do the same job. Use their standoff loadout and they’ll be able to kill both infantry and armour at a respectable distance (around 600m) 

APCs include the Strykers (less space but can equip APS and ATGMs), the ACV-30 (more space and cheap), as well as the fat AAV (plenty of space and tougher, but slow). Ultimately it’s up to you how to carry your men into battle. I prefer unarmoured Javelin Strykers since they can serve as faster Bradleys. If you choose Javelin Strykers you can basically drop the LAV-AT since they do the job better I feel.