This is possibly me misunderstanding something, but I've got an outpost with 65 drillers and 4 shields being attacked by 79 drillers, a helmsman and an assassin.

Scrolling forward in time shows the outcome I lose the outpost and the attacker has 34 drillers left. When I add it up, I think he should only have 10 drillers left. Neither of the specialist seem to have an impact on the drillers.

Am I missing something?

there are some specialists with global abilities that could affect this. tap the combat preview button in the sub's info panel and you'll get all the details of what's going on exactly.

Ah, that's it, he's got both an engineer and a general. Appreciate it.