I think a lot of folks are trying to figure out who the "canon" Gale is.

He can go either way as the main character. The player can make him good or evil or whatever.

But who is he as a companion? If left to his own devices?

Unfortunately, I suspect it's not that simple. I think just interacting with Gale is going to have an influence on who he turns out to be. I think Tav can influence Gale to go down a dark path, and I think Tav can inspire Gale to be a better version of himself.