Commandos are a bit too good in my experience. (Maybe reduce their DPS and give them a bit more durability? I find it hard to react at how fast they kill squads.)
Brits need some sort of light and mobile artillery as a basic unit imo. (The mortar emplacement, while powerfull it is expensive and prone to get quite easely killed by Leigs, although if Leigs and Pack howies get nerfed to a degree where people dont build 4 of them per team then a new light arty unit for the UK is probably unnnecesary.)
Trenches shouldn't be able to build outside your own territory, much like US fighting postions (imagine if those could be built anywhere.)
The Leig and the Pack howtizer are both absurd by how they supress units so easely, either remove the supression effect or give them a huge supression nerf.
Centaur should maybe have a slight DPS nerf and a bit more mobility.
Mechanized company needs a buff