While we have the M4 High Speed Tractor in Game in US OBAT012 (Unit 381); we don't have:
M5 H/S Tractor
or
M6 H/S Tractor
Reason I raise this is I found it while setting up a Okinawa scenario -- apparently the Army had started to convert divisional 105mm Howitzer battalions from being 2.5 ton truck-drawn to M5 HS Tractor-drawn, due to their experience before and during Okinawa in actually moving heavy loads across muddy/rice fields.
There is also a USSR (OBAT011) connection:
https://soldat.pro/en/2019/01/03/dry...ii-traktor-m5/
Apparently 200~ M5 H/S tractors were delivered to the USSR from 1943 onwards, enabling them to equip three artillery brigades (39th, 45th and 46th Cannon Brigades)