I thought about some cosmetic and game mechanic things that really should have been fixed a long time ago that, I guess, fall into this design thread.
First, models stances. Coh2's squads just feel lifeless, models stay on their feet while being shot at and just dont show any sence of being in danger or concerned about the enemy being nearby and look for him. Making models crouch behind cover and go prone and crouch when fighting would improve CoH in this department.
Instead of this:
https://steamuserimages-a.akamaihd.net/ugc/527262038870658708/812246A743F1D64A38F2F8CF8A7FA942AFADBAFE/
More of this:
https://vignette.wikia.nocookie.net/companyofheroes/images/c/c1/Unit_Infantry_Section.jpg/revision/latest?cb=20110724212121&path-prefix=en
https://vignette.wikia.nocookie.net/companyofheroes/images/d/d1/Stormtrooper_%26_Sniper_02.jpg/revision/latest?cb=20080902233047&path-prefix=en
https://vignette.wikia.nocookie.net/companyofheroes/images/d/d2/Unit_Luftwaffe_Ground_Force_Bright.jpg/revision/latest?cb=20110727172433&path-prefix=en
Secound thing that would improve CoH is if units like the sturpanther and flame based weapons would target the center of the squad, this way using their weapons to the fullest without forcing the player to attack ground.
Another topic I wanted to talk about are mortars. Mortars right now don't require as much skill as, let's say, using a hmg. Why not make the player have more input in what a mortar actually does for him? To achieve this I suggest removing autofire from mortars, remove the cooldown from the barrage and give suppresion (if a mortar round exploded next to anyone that person would suffer some kind of supression effect I would way) this way making the game a bit more realistic, rewarding a player for using a mortar well and giving a more stratigic role to mortars (instead of "hammers").
Edit: Also apply the same "killing models limitation" that mines have to prevent mortars from wiping squads that are too clumped up.
Finally lets talk about blobs. I believe blobs are a valid tactic but the only way to counter a blob is by blobing yourself because hmg's (the logic counter to a blob) just die before doing something. My suggestion would be to use a mechanic simillar to the shared veterancy but instead it would share suppression. Lets say that a hmg does suppression to a squad at a rate 1x. Now imagine a blob of 5 units, with the shared suppression the hmg would do 5x the suppression to each squad in the blob because each squad would share suppression with the others and thus hmg's would finally do what they are supposed to do, counter infantry.