The M3 Grant/Lee tank was an interim measure until the Sherman was fielded as the standard US medium tank. It was used in combat by both the Brits and the US Army in North Africa (the Russians used some lend lease ones as well). It was a useful training vehicle and, like the Sherman, was reliable from an automotive aspect. As a fighting vehicle it suffered from inadequate armor, a high sillouhette, and an inadequate main gun with limited traverse (although the British liked the 75mm HE round against German anti-tank guns).
These are nice photos from a PR point of view. In reality the crew of a disabled tank would get away from the vehicle rather than dismounting and trying to defend it with revolvers and SMGs. If the vehicle was a mobility kill with the armament remaining servicable the tank could still be fought using it's weapons as long as ammo was available.
The Thompson is a Model 1928A1. These were produced into 1943 when they were replaced by the simplified M1A1. Thompsons were issued as on board equipment for US tanks until replaced by the M3 "Greasegun".
