Tell me what you want, what you really really want! ...Oh wait, you just did.
Yep, because mass lock is based on... mass, not size. A super dense, small ship could theoretically have a high mass lock factor.
Back in the old MS-DOS days, there was a very difficult game called Epic. Basically in the far future, the aggressive Raxxon race is trying to exterminate humans, and the sun is about to go supernova. Humanity's only survival option is a mass migration through hostile Raxxon space to the nearest habitable world.
To accomplish this, humanity uses their entire stock of... well, a super-rare meta-alloy, basically, to engineer three heavy superiority fighters, which you, as humanity's best pilot, must pilot and safely see the convoy through to their destination in a variety of harrowing deep space and planetary combat missions. Great game, never did beat the final battle where you have to save the human fleet from literally hundreds of enemy spacecraft.
I had EPIC on the Amiga. It was quite impressive in some ways, but could be bloody frustrating. I recall it being rather buggy. But it was basically battlestar galactica in game form!