It's a shame the tank riders are metal, when the tank crew is plastic, although they look like nice sculpts I've found metal really doesn't work for tank riders (for wargaming purposes - if you want them removeable).
In reality, it is quite difficult to sell enough to make our tank riders to be plastic, so we compromise with better sculpts with more details.
What's the chance the US TD crew would work with the Warlord plastic M18 Hellcat?
Never try that out ourselves. Should work as our TD crew is designed to get fitted into very cramped spaces.
I assume the plastic Rommel is the same as the one in the command halftrack expansion?
Yes, it is the same sculpt with an extra radio operator. Many people asking for a standalone version.