There's a Tau Wishlist thread that's running on Warseer, and they've come up with some interesting ideas there. There were two suggestions that were brought up that might be in for perusal for the Kroot.
If you use Kroot as something more than a speed bump I don't thing they need that offensive change. (As this is a wishlist and not tactica) Kroot work best parked in cover and acting as a counter attack unit, pumping out fire then receiving the charge. Id rather they had some sort of rule that means they ALWAYS strike simultaneously with attackers, even ones with assault grenades.
How would you feel about an 'ambush from cover' rule to get the first attacks during the first round of combat and then revert to normal rules after that?
I ran them together for the following:
Ambush From Cover: Kroot's chameleon-like skin allows them to blend in with their environment. When either assaulting from a position of Cover or being Assaulted in Cover, all Kroot models Strike First for the first turn of combat. Otherwise, if not in Cover, for the first turn of close combat, their close combat attacks always strike at the same time as their opponent if the Kroot's Initiative is the same or lower (so still beat Boyz and Fire Warriors).
It may be a bit over-powered, but an interesting idea, nonetheless, eh?