Here is my actual choice for pact infantry in my deck, i would gladly receive any comments or advices about it.
My main pact set-up:Rifle Squad:
Motostrelki + BTR is good, I've noticed that most Pact players have them in their deck now.Shock Infantry:
Definitely Motorise Schutzen, they are superior to Spadochroniarze in every factor besides transport. But if you want better anti-tank shock troops, with the same fast transport, check out the Vysadkari.
Personally I prefer the 4VPZU, because they fill the role of "Special Forces" more, they can quickly and cleanly wipe out a single target and dip before the enemy can organize a counter-attack. However, Grenzers can be placed in random locations (like buildings/forest of no importance) across the map, allowing you to see what the enemy has before or after their advance.
Heavy Shock Infantry:
Spetsnaz might be the King of the Jungle, but after finding out about the 4VPZU, I don't use them anymore, because I rarely fight an enemy that depends heavily on infantry. It's a good choice, because I've seen a lot of very good Pact players use them extremely well. If it's the cap that bothers you, maybe you can replace them with some other heavy infantry, like MotostrelCi. (or assault engineers)
Generally speaking in terms of AA/AT, it's best to go for the anti tank teams with the best anti tank weapons, regardless of price or quantity. But hey - that's just me.