Top one is the M-18 Hellcat, the best TD of the war, bar none. 65 mph road speed, 76mm shooting HVAP ammo. German tankers feared this little monster more than the Sherman Firefly. There are stories of these thing tearing through gaggles of Panthers like mad dogs. Impossible to track once they start their dash, it had a stabilized gun and gained many kills while racing flat-out cross country.
Lower vehicle is the M-36 Jackson. Basically a seriously up-gunned M-10. It's 90mm could kill anything it encountered.
Both were used from ambush to great success. The Hellcats used "shoot and scoot" tactics to perfection. Of all allied armored vehicles deployed to the ETO, the Hellcat had the best kill to loss percentage prior to the M-26 showing up in 1945. I read the memiors of an M-18 gunner, who described the TDs ability to maneuver behind a Jagd Panther thru sheer speed, pumping a HVAP round into it rear before the German crew could figure out where it had disappeared to.
Having thin armor, the Hellcat would never fight a straight up duel. Instead, they simply raced around the enemy and "hit him where he wasn't".
For all its success in the war, I don't see it being used as intended should HTC include it. Most guys haven't the patience to sit in ambush. Both it and the M-36 would be terrific spawn campers tho. And with the Hellcat's speed, it would very hard to hit, even over open ground. However, if HTC models its stabilized gun, it would be deadly, even at full speed.
My regards,
Widewing