I've had many PGren spams lately and have found that the best way to counter now is T70.
Tech to T1 get flamer truck, deal with MG's in building (PGren spammers like to stick MG's in buildings as support units). Then get T3 and a T70. Most PGrens won't have Shreks as it's too early, then back tech to T2 for a maxim and AT. The T70 will wipe out most PGrens or make them retreat due to lack of Shreks. Then pump out more T70's or tech to T4 if you have enough resources. I prefer to spam T70's and ram any Panzers or use them as bait to go near my AT gun.
