I know that it's not kosher around here, but the jump drive physics explanation in the Wing Commander (movie) Confederation Handbook does a pretty good job at explaining how fighters might have jump drives...
To simplify, fighters can do short jumps, capships can do long jumps. Has to do with the energy needed to travel the jump line - there is an explanation that if one were to run out of energy during a jump, you would be stranded in the void somewhere... So to carry that bit of info to it's conclusion, the engine size and power of the craft would dictate which jumps it would be capable of. Might mean that a small fighter has to take 'the long way around'.
Now, what I want to know is the physics behind the scene towards the end of WC4, when the Intrepid (chasing the Versuvius) as a "...smaller ship, has other options..." There follows some random talk about 'fitting through' a jump point. What? Has space got 'low bridge' signs now? That was the worst plot device ever. I'm gonna make a big call and say _Worse than all the mistakes of the Movie_.
[awaits flaming bags of poop]
M.