I tried all factions and i find grenadiers to be the squad with the largest reward-risk factor. they are strong, but so hard to use in the heat of battle.
I think AEC comes early enough if you have average fuel control and offers a more mobile anti vehicles option. if i see double panzer 2 or triple 222 or if i smell a puma coming i get the AT to support the AEC.
one situation i feel when AT is better than AEC is against flak halftrack, since the flak HT needs to be immobile to fire, giving your AT the chance to return fire.
On my side, I would propose that you drop this idea of having a usual build.
3 volks into tier 1 is not always a good choice, specially against SU penals and USF Riflemen.
it is 99.99% incorrect choice to upgrade the Sturms with the shrecks, since you loose on sweeping, faster repairs, anti infantry dps. the 70 Munis can be used in better things like 2 Mines or STG upgrade to 1 Volk.
It is also not always good to go for both tier 1 and tier 2 before you get your first tank. Dont forget also that an early Tier 3 will help you lock down a section of the map, just dont go creazy with it and prepare an emergency plan per map to save it if it comes under siege.
Going Jadg or panther should not be automatic, Jadg is good only on few maps or if you are up against tank destroyer spam, Panther is useful against heavy tanks. The OKW P4 is a much better tank if you can get it somewhere before 15 minutes mark, due to its superb armor.
pathfinders are good at scouting MG location. I have a friend who use them to great effect like that. stop trying to turn them into some sort of gren like squad
this is a normal brit opener on crossing to get a vicker and a UC.
the solution is simple to state but requires mind presence : if he locks you out of both fuels, this means the 2 cutoffs are not well defended.
try to train yourself into cutting the opponent of if they are defending the ressources and the opposite if they are defending the cuttofs.
keep a gren near the 222 to defend it from the AEC.