LT (280 mp 25 fuel): m20 (skirt locked), 50cal, 57mm, pack howitzer
captain: stuart, m17 AAHT, m20 armor skirt
remove mortar
the USF can get their support weapon relatively early through the LT with m20 support and either get the captain or skip it entirely.
Instead of having 2 versions of the m20, the captain could just have the M20 and M17 AAHT, with the Stuart unlocking when either the LT or Major is called in.
The LT could have the MG and mortar, with the pak howitzer and 57mm unlocking when either the Captain or Major is called in.
LT fuel cost to something in the 20-30 range. Captain cost to 50.
Weapon rack and Grenades could see an increase of 5 or 10 fuel to reflect the lower teching costs.