The german one takes 3 AT nades to kill and takes no damage from rifle fire. Not only that but once you get close enough to throw AT nades your men are dying from the flames. Guards come a bit late. I usually just wait for a T34 to come out when dealing with the halftrack.
Theres a commander with Rifles lvl 2 and another with rifles lvl 1. Lvl 1 should be way faster than T34 in most cases. Maybe the flamer halftracks still will be earlier than your rifles if he is rushing for it but then you have to retreat and regroup for attacking together with the rifles a minute later. Shouldn't be that hard.
As for germans early I reserve 70 munitions for fausts except on extreme conscripts rush then I upgrade Grenadiers instead fopr all munitions. And as soon as I got tech 2 I build a Sdkfz 222 scout car to deal with those.