I haven't watched the attached replay, but I would swap Mgs, with grens in your build order simply because these can not only dominate chokepoint areas but devastate infantry moving through open fields, whereas Grens are going to cost you munitions before you can counter the higher rifle numbers. That means you're less likely to end up running around behind the frontlinechasing down engineers and scouts who slipped past.
Have you tried adding any mortars to that strategy? I personally find them really useful for adding that little bit more firepower to any infantry battle, and they're also useful for fending off light vehicles, or even adding a couple of effective attacks when faced with a medium vehicle.
Remember, the AI is much better at capping and moving around erratically then a human player, so dont panic if areas get cut off unless you are in a bad situation...
If you're having troubles with being outmicro'd behind your frontlines, I'd try keeping an assault squad in a half reserved position, or even a light vehicle; beng cut off in itself is a bad situation both economically and combat-wise.
if the allies are using arty to snuff your AT, then they are not using it on other more dangerous abilities such as Field Repair or AWM.
If your enemy is expert they'll be buying anything they want with their resources

and Col. Tiker is right, the AI calls artillery in on your positions, not on what it can 'see'.
This strategy is very balanced, I think it would work best as a basic structure for PvP fights. It's a shame the AI is broken with 2.5xx versions else I'd like to test and use this against the usual tank-spam
