Brook would destroy him IMO. Rios won't do anything at welterweight. for a pressure fighter he mosly throws single shots. Never really puts any proper combinations together.
Brook is too BiG and reportedly moving to 154 Rios is a puffed up lightweight looked flabby and slow at 147
This is a fight Hearn will look to make, no doubt about it. I like Rios, tough *******, but Brook will knock lumps out of him.
If Hearn wants to bring him over he'll have to dig into his pockets. Rios earns well over in the US and won't come here for anything less than around a million dollars. Somebody like Diego Chaves (who IMO was ahead on points v Rios) would be much cheaper....