I ran some tests with the rebel valhalla hull against the praetorian hull stripped of all bonuses so its just the size that matters.
4 x heavy plasma launcher (modded to 0.05 tracking speed)
3 x ultraheavy armor
1 x basic powergen
1 x crew module III
1 x engine II (modded to 1 thrust)
I decreased the engine thrust to make speed a factor without them going out of position and decreased tracking speed to compensate.
10 trials were done, and I recorded the potential damage of missed shots
more than twice the difference… good luck covering that up with 10% of shield boost…
not to mention that the valhalla has 7 percents in it self also…