That was it! ^_^
The tanks go into battle, shoot and die successfully!
(Minigun needs a fix though because it's using the wrong bullet sprite and sound, but that's fixable)
Thank youns SO MUCH for the troubleshooting! Now for the next tree of ranks *rubs her hands together and giggles)
Spoiler: Hoping to make this work with xeno operations and compliment it's other trees and improve HWP lifespan throughout it