People are dismissing Dengar on Boba.
Boba doesn't want to be at range 1 of too many ships, unless he can bump one, or dodge arcs, because firesprays are fragile against mass fire. Getting more than one or two innate rerolls is unlikely without also risking massive damage in return. If you're trying to catch something fast like aces or other large base ships, being able to get rerolls and still use EU is pretty useful.
Dengar means that Boba's shooting is frequently action independently completely rerollable, freeing up your actions for what is situationally best - and it's cheaper than gunner. It's less able to capitalise on stripping tokens, of course.