These are two of the scripted leaders I've seen so far and IMHO both were useless. (Agree about the general.)
Maybe the governor would have been better if I'd been using slaves, but slaves seemed like a bad idea on every other planet, and I've got no way to enslave pops on only one colony. If it was a sector or even a system bonus then my opinion might be different, but a low +% to one worker type just feels like a waste.... even though I had a planet with 27 mine districts on it (thank you Orbital Ring), he wasn't making enough difference to justify losing a science ship.
Maybe I should have enslaved a big population of primitives, kept them on their homeworld, and sent him to govern them? But then I'd need the ~20 natural mining districts to appear on a homeworld and that seems even less likely than the absurdly lucky planet I found that time.