I actually like these a lot. At first I questionned the utility of Sparks in your sub-team, but looking at him with and without the helmet, I see now that this is exactly what Sparks would look like if he got a bit more muscle and rapid deployment training. Good job. And the head feels right too.
I also like how your Rapid-Fire is a loyal translation of the 12" series figure. Down to the colour of the hair, he is Rapid-Fire. You know, this is something that I enjoy seeing in custom work: when Joes of other sizes are brought down to the 3 3/4" or 4" scale shall we say, we can finally appreciate what Hasbro would've been able to accomplish in an alternate reality had it not been for a question of timing and sales factors.
Urban Infantry trooper is well, still Resolute Firefly to me. Always a pleasure looking at your work Nighthawk, so keep them coming.