J-20 is a multirole jet. If they are calling the F-22 multirole, then J-20 is far better at ground strike than the F-22 is in terms of weapons options.
J-31 is a pre-5th gen jet according to the Chinese. Nothing insane about it. They literally called it a "pre-4th gen jet", their term. And they have clearly said the jet has been made for export. So what this means is it will be 5th gen or higher depending on how much is spent on its development.
If PAF says they want only 30-40 jets, then how much do you think China will spend on the jet? They will just give it basic capabilities that may not even be 5th gen. Make a commitment of about 200 jets like you did with JF-17, then we will see if it will be developed to 5th gen standards.