Makuhita has "Fluctuating" EXP growth, which starts out the fastest and becomes the slowest. You can compare with Machop's "Medium Slow" growth
here.
From a glance at the run, Machoke is Lv43 after Sidney. That's >71833 exp, so Hariyama would be Lv41 instead. Huh, so it would be
fewer level-up messages.
On the other hand, he'd be getting more "new move" messages. Here's my estimate:
Lv16 Machop: Seismic Toss, Foresight, Revenge, Vital Throw, Submission, Cross Chop (6 total).
Lv06 Makuhita: Arm Thrust (4th move), Vital Throw, Fake Out, Whirlwind, Knock Off, Smellingsalt, Belly Drum, Endure (8 total).
...Oh wait, +50% exp for traded pokemon. (I knew that!) Machoke beats Steven right before Lv50, so with the same EXP Hariyama would be over Lv52, and would have a 9th message due to SToss (Lv51). Starting off he'll need 1630 extra EXP (2445 / 1.5) to catch up to Machop's Lv16, too. There's also all the instances of "boosted", and Hariyama's cry being longer than Machoke's.
Base 120 Atk versus base 100, higher levels so better damage, obtained earlier... yeah, I dunno! Good suggestion. You'd need 286 exp (pre-bonus) to get Lv10 and Arm Thrust for the first gym, though. Also, Makuhita catches up to Machop in EXP at Lv22.
At any rate, it could be entertaining to use disobedience to pick other moves for you. For example you could pick a fighting move against a ghost, make the crowd "wtf" and Hari uses Earthquake instead.
