Apbt? Clearly not, a bully grey is more like it, and even then I'd say the average bully grey is too bully and bulky. 

Apbt is just the ultimate boucheries. 

I think in general you underestimate how athletic and fast all alaunts were as dogs of the hunt, the LGDs you consider comparable to veantres and boucheries are far too big and sluggish, and a gentil is described as basically being a gripping greyhound. Probably comparable to a bully grey x grey.