Turns out you can go T1 to T3, mass guards and use that as your main form of AT. A few T70s for AI an possible one T34 and you have a fairly strong army composition. Marked target plus guards take out a P4 super fast, throw in a button for good measure and its a done deal.
And if you didn't take a GR doctrine??? Also, what if the OH-player is a genius and builds a mortar or two? Or even has AoE Inf removal in his doctrine?
Infantry doesn't work as Armor removal in this game, because by the time armor rolls onto the field they start dieing like flies thanks to the countless Inf gib abilities. While we're here: Why are there so few abilities that deal with armor? And why are the few that are there so weak?