no one its not every day you can grab a ww champion and the fighter of the decade with the amount of speed and power he has of the street............... its easy to mimic duckweathers style bad hard to fight someone like pac who punches from all angles with BOTH SPEED AND POWER SNAP SNAP SNAP PUNCHES
To be honest, Lomachenko has the foot speed, footwork, and athleticism to convincingly mimic Pacquiao's style. Too small, though.
Floyd said that he doesn't care who his opponent is. They don't have to watch film or specifically train for it. He adapts on the fly or something like that.
You just pick up any guy in the street tell him to run like hell inside the ring that'd be like fighting Floyd. So Pac has no problem looking for sparring partner :smoke
Ricky Hatton fought a lot like Pacquiao but didn't have the power or the chin. He had the aggressiveness and used in and out movement, angles. No one is exactly like Pacquiao or Mayweather though so there isn't anyone obvious for Mayweather to spar with. Errol Spence is good sparring but nothing like Pacquiao. On the other hand Pacquiao can spar with Rigondeux to prepare for Mayweather.