I'm sure you've seen this, from top to bottom boucheries, gentil, veantre.

Now compensating for the inherit crudeness of the carving, it seems clear to me the boucheries were quite like pitbulls. Which makes sense, this is the type of dog ideal for swinging on a bull which is proven still today in the line of work. 

The gentil's depicted here are actually sleaker and faster than even bully greys, which also makes sense to me, because frankly a bully grey is not as ideal for deer coursing/catching as it would be if crossed back again to a greyhound or deerhound. And this latter dog type could still be used on boars too. 

The veantre is basically like a presa or bandog type, again compensating for the crude artwork typical for the time making all dogs look kind of silly and spaniel-ish. And again makes sense, this is the type of dog ideal to catch and subdue men and also a good type to back up boardogs and stop big boars from fighting.
None are really huge, all have to be somewhat athletic for their roles, the boucheries here are lean and streamlined just like good pitbulls, the gentil leaner and more streamlined even than a typical apbt x greyhound, let alone a pure apbt. The veantre more like a bandog than a neo or english mastiff, even the average boerboel or bullmastiff of today too sluggish and slow to be a real veantre. Veantres were probably usually around 110 lbs, boucheries 60-80, and gentils 70 - 100 due to being quite tall. These are typical working weights for these types.

All these 150 + lbs dogs you see pics of on the net are a new thing and really good for nothing, that is unless we're talking about LGDs which pressumably can work well at quite large weights and probably always were quite large (although many today are still exagerrated and beyond a serious working size). They perhaps naturally ranged from 100-150 for very tall individuals.