rather have a GSD, with the above x, greys+ bulls arnt guard dogs, and it will only be a (1/4 % about) presa,so regards as a guard waste of time. And for work maybe maye not, plenty of good proven bullxs about.! Still, what floats your boat.??
mmmm there is a lad down the rd from me does a dog very well ,,,makes any type of dog go mad,he would make any type of dog guard,,bull grey any thing ,,dont ask me what he does to them but once he got em going you can not get near them ,,so think the above will guard etc,be honest if you saw a big dog running round lose you would think twice about go