If you want a Marauder, I would suggest that you get an Orion Galactic (something ... that Huge ugly ship), and the largest (not necessarily the best) fleet. This is for capturing percentages. Three Black Lightning shots will neatly disable the Marauder. Note: the Marauder is a killer and does not have enough of a crew to capture well ... so I would suggest that you capture a few Alien Command Ships first, then your Marauder. Two B/L will disablle a Command Ship.
Beware, the rules may have changed. The authors were a bit disturbed (earlier convesations) that some or us were able to fly the Wraths and Marauders, which were susposed to be out of reach, and may have changed the math.
You will find, however , tha t when fighting you only opponents, another Alien fleet, that you have to use your Marauder in a defensive fole protecting you r Alien Command Ships from Alien Attack Cruisers. The Command Ships are surprisingly vulnerable.
Boy, the Marauder with their Alien Fighter/Bomers are powerful, but NOT invincable.