Well, the OP might not have made his point very eloquently, but, i do think Volks with their STG's and with some vet might be too cost effective. The trouble being any over-performance of this unit is totally overshadowed by the outrageous performance of units like the Scot and Brummbar. Additionally, the easy access to, and pervasive allied meta of using light vehicles helps cover up/make up for any *base main line infantry* deficient in performance on the allies side.
Note: im not talking about any commander specific or other elite infantry, only basic infantry you have access to early in the game.
Arnhem Checkpoint is at its core a good map. It offers good structure in both the sector layout and the fighting spaces. Good cut off play is possible while not overly dominant, with so many good flanking routes while not overly open. I think with a good rework on certain areas of the map it could be a fantastic competitive offering. I would like to see it kept in but with changes made.
I think Minsk is pretty much a LoL map; three lanes. Its shapeless and leads to camping in both 1v1 and 2v2. The flanking routes are either too close to base or easy to block off with wire or munitions. As such it generally favours the factions with the best long range capabilities. I find it difficult to see how this map can be changed to resemble a balanced and nuanced map without such an extensive rework as to make it a new map.
Sometimes people get scared of losing, both units or the game as a whole. If he cant get out of the mindset of taking no or minimal risks, maybe competitive gaming isn't for him?
Try and get him into a 1v1 against yourself, or others actually. That is the best way to learn as the mistakes and successes are the individuals alone.
One possible line of reasoning could go like this:
The longer a game goes on, and the more resources you let your opponent hold increases the likelihood that you will lose, as any earlier mistakes become less impactful the longer the game goes on and the more chances your opponent has to turn the game around.
I do think suppression and HMG's (and LMG's too) could do with a fundamental rework. Your idea sounds promising, although i kind of have a problem with the idea of a squad getting wiped at long range from a HMG
Otherwise some kind of rapidly enacting suppression zone that player has to demarcate would be pretty cool.