Scarlet, 'twas the "statwise similar to Cass' fighter" that did it. tpt wanted a very light and fast fighter, so it had no payload option.
I'll allow a re-design if you want; just take another look at the options two or three pages before the link you gave.
Eerin's assessment seems very reasonable. Within the shield, the artillery could shell the arera around the generator until it blows.
But to destroy the personnel would mean going out and attacking it. Which once more gives the Imperials what they want- you leaving the walls.