Round 1:

Reptile easily sneaks up from behind and injured Guile

Jax and Balrog have similar strength, but if both hit with the attack increase, the metal arm of Jax breaks, while Balrog goes KO. I think Jax wins

Round 2: Reptile moving so slow is probably very fun to see. Guile can Sonic Boom Reptile from the distance or defeat him from near.

Jax is probably a bit slower than Balrog, so after a long and boring fistfight Balrog does more hits, but they're weak if they're so slow. Jax on the other side can grab Balrog'c throat and break something.

For Balrog there isn't a

Round 3: Reptile relies on fast Critical hits to defeat low HP-enemies with a few attacks. But Guile has more durability and wins this fight.

Soldier heroes win