Memory serves, Defilers have 2.0 fire rate compared to Colada's 4.0. Maybe I'm wrong and they have equal fire rates, but that halfs its fire rate and still ptus it beneath Coladas.
Regarding power plant usage, throw four on a bomber and you can down a foolish Battleship's shield solo. Back in .84, anyway. Might have been changed.
On the pirate generics, yes, their own line would be good. However, they are pirates and should be focusing on pirating. Most of that can be done with a Supernova and quite a few of them use an Inferno anyway.
Meh. Maybe I'm just biased. But I've seen many times a set of debs unloading on a shield have been bested by one or two Coladas which only get in a few hits.