IIRC Vaughan had better service pre-COVID on the Barrie line than Brampton did on the Kitchener route.I dunno. Queen and main seems to have as much, maybe more intensification, than Vaughn does (with Vaughn currently trending to surpass Brampton with the VMC project though).
I see the difference between the two being their relation to Toronto and the ttc system. Vaughn being directly north of Toronto has many bus (and now subway) routes that cross the municipal border, while Brampton does not. What Bramptondoes have, however, is greater connection via the go network (side note. This could be evaluated on a municipality or regional level, and I'm going off the top of my head, but I'd say off the top of my head that brsmpyon has better go service than Vaughn does).
So I would say that Bramptons goal should be to focus on intensifying its historic downtown and the areas surrounding it's go stations.