The Leech Turret was meant to act like its mobile version manifested with the Hammer Tank but with the difference that it should be able to leech 2 weapons, re-store to default no-leech weapons and such... All of this turned out to be impossible (aka I have no clue, maybe it's possible but I didn't felt to try on for 1 more year).
Eventually, it got replaced by the Flak Bunker in the beta release.
Shame sounds like a great idea.