Don't worry, someone will be along to explain that P4P rankings aren't 'how fighters ranked based on current form and rankings placements' (which they should be), they're based on how each competitor's skills translate across different weight classes (which they shouldn't be, and which nobody has ever asked for).
Trust me, these sites often have completely arbitrary interpretations of P4P, when what everyone wants to ACTUALLY know is 'who is doing best regardless of weight class'.