I hardly ever get Pro to be honest, not for the first four or five skills at least. A skill I'm not going to use on most turns and that only has a 50/50 chance of letting me retry something else (rather than being an action itself) feels like a bad deal, doubly so when it stops me using a team reroll - though loner could do that it's only got the same chance of stopping me as Pro has of succeeding. I'd rather get something like block, dodge, tackle, jump up or side step.
I've yet to find a good, reliable role for aggressive big guys, they tend to act like turnover generators. Generally I prefer the more passive types like the Beast of Nurgle.