Maul: 16,000 (I think he was supposed to have a lot of potential)
This could be way off but thatís kind of my idea of where each of them would be at in terms of raw power/potential.
Registered: Jan 2020
Location: Chiss Defense Fleet
Rey and Kylo would be equal imo.
Also brings up an interesting question, because wasn't Maul's potential pretty absurd in canon (like could have been a peer to Sidious)?? Because in that case it's possible he had a much higher midichlorian count (lets say 19000), but simply never realized his potential.
In The Tenebrous Way, when contemplating the possibility of the midichlorians giving rise to a "chosen one," Darth Tenebrous speculated that such a being might possess as many as 15,000 midichlorians per cell. In other words, naturally being born with a midichlorian count of even 15,000 was considered to be completely impossible by the universe's leading expert on the subject; I wouldn't be surprised if most of these folks were <10,000.