The enemy ships have a low (20%) chance of having Afterburners, and a 0% chance of having Maneouvering Thrusters.
I suspect that this is one of the reasons why the enemies get easier as the levels get harder.
My ship carries 2 sets of Maneouvering thrusters, and one Afterburner, ALWAYS. Thus, I can turn my ship MUCH faster than the Sithrak.
Like, I can almost chase fighers...
Certainly can run into them almost at will.
Something else to try...