I agree with this.
The Governor seems just like some poor guy who went manic due to the loss of his daughter, perhaps sociopathic, though that may be a bit far. However, Negan appears to be almost undoubtingly a psychopath. Charming, manipulative, meticulous and with a general disregard for the lives of others coupled with a distinct lack of empathy.
If Negan discovered the Governor's secret about his daughter, which he no doubt would, he'd be able to mold The Governor like putty in his hands. No doubt, Negan, with both his undeniable wits and lack of care for anyone altogether, would dominate The Governor.
Also note, Negan has a far larger group under his control than the Governor did, and many of them have very antisocial personalities much like Negan himself. You know, the whole "I am Negan" thing going on there. Many of the people with The Governor weren't as keen on trying to kill and ransack other towns as Negan's goons are.