It would be nice if Tommies at least had to pay a munitions cost to upgrade Bolster on each squad, I get you have to pay 150 mp and 35 fuel but British Tier 1 tech is only 30 fuel so it standardizes their tech costs in line with the other factions in the game. Make it 30-40 muni to upgrade so if you want a double equipped Tommy Squad that can heal on the frontline you have to make a significant munitions investment which should at least cost more than double equipping Riflemen since they don't get the same cover bonus.
UKF is already spending a lot of muni, perhaps too much. This is mostly because of commanders, which almost all come stacked with expensive abilities and call-ins with muni ugprades. Anyway, I highly doubt UKF currently needs any more nerfs now. Tommies, Comets, AEC and UC are already getting hit in the economy department.
I think that could help tone down Tommy spam a bit since you rarely see people going 4 Riflemen but 4 Tommies is standard. Especially with Brits not needing medical supplies on every squad now since the Medics were buffed to perform AOE healing like the ambo. I would be ok with the medics being made 2 pop cap to mimic the pop cap of the Ambo.
USF makes less rifles because of officers taking up the mainline infantry spots in the composition. UKF is forced into 4 sections because there are no stock or call-in mainline alternatives except for officer, who is currently a bit of an expensive and risky pick.