They both get re-rolls, but can someone walk me through how they work together? Or do they?

When attacking you choose which one you would like to activate first. You can do Dengar > Boba, Boba > Dengar, just Boba, or just Dengar. Any individual die can still only be re-rolled once no matter what.

Got it, Dengar can't re-roll a die Boba rolled and blanked on. Probably overkill to have both, and time to look for another way to spend those points. Thanks.

It might be, but only if you have more than one (for a unique target) or two (for a generic) ships at range one. Otherwise, they synergise rather that duplicating.

K4 might be better though. K4, cluster missiles, guidance chips is pretty potent on Boba.

K4 and Clusters sounds pretty sweet, I'll grant you, but K4 on Boba in general is even more anti-synergistic than Dengar on Boba, because a Target Lock can already rereoll any number of dice.

Tail gunner or tactician are both good choices on a firespray, and Boba might want fearlessness as an ept...