Engineer Turrets
Turrent recharge when picked up should depend on its health. With full health it should be minimal or even no cooldown at all, while destruction would give full recharge.
This will also make the wrnch more useful, and a valid option compared to the turrent self-healing trait.
Of course, to balance things out, the turret-self healing would give additional recharge to turrets, something like +10s, since with it it’s more likely to pick them with full health.