thanks for checking the game! the turn order is based on the mech & pilot's speed stats. The enemy grunts are very slow (the boss is quite fast though) so there might be cases where you can move twice before those grunts start their turn.
Is the game too hard? At the moment I'm not satisfied with the hit/miss formula because the miss rate is too high (only around 70% chance to hit a grunt? seriously XD). Thankfully the same formula is applied to the enemy so they also has a hard time lol.