1- You always have a doctrine which can 1 shot Howitzers on teamgames. B4 was a bad unit design but it's non issue since it lost it's precision strike.
2- Unless you provide a replay of the game you had issues with, i think nothing you are complaining for is an issue at the moment.
If you are main issue are Guards buttoning, you pick a doctrine with smoke. Having any indirect fire destroys Guards as they can't do shit on the move.
You don't push Guards with PGs. They are defensive unit and PG are not an "assault" unit. At least not against any unit with decent DPS (unless G43). If you can drop at them from cover/shot blocker sure do so. But no in open field.
You don't spam PIV to deal with T3485.
Mark vehicle problem is that the debuff is not tied to the plane been alive or not IMO.
B4 is still meme/niche.
FMR + Penals PTRS. Penals late game are only snare units. If he has more than 2 he has no AI.
From the rant, it looks to me like you play random 2v2 and you might possible be facing an AT team.
Non Issue I lost 11(no joke 11 tanks 5 ostwinds 4 stugs and 2 p4) tanks 1 game from B4 standerd barrages, no vision near max range all.