I agree Ladyhawk, I do think it's very likely that our Percy changed his name around to suit, He clearly fully intended not to be traced, and he's done an extremely good job of being elusive, so far!
Thinking about it, I only have the information regarding George Ball on Percival's marriage certificate to Sarah, this may not necessarily be correct. It could be quite possible that the 'George' mentioned on the marriage cert isn't Percy's father but maybe another relation he'd named, or perhaps he didn't know his father very well and was told he was named George and was a master butcher?
As regard's Percival himself, I think he may have originated from outside the Staffordshire area, and may have left the area after leaving Sarah Ann. If I'm fortunate enough to find the clipping of the 'possibly' correct Percival Ball, I will hopeful have some clue to his origins and family.