Hitbox and mobility are huge factors into wether a person is 150, 200 or 250
Take tracer, she’s extremely mobile and can dish out a tonne of damage with a TINY hitbox, she’d be so broken with 200 hp (even though she has effectively up to 299 hp with recall lmao)
Take McCree, he’s slow but an average hitbox size, and he has a flashbang stun to defend himself with and a small roll to help peel. Not needing 250 health when he has such effective range
Then take Reaper, he has almost no range at all and a slightly bigger hitbox than most, slight liferip and the choice to take no damage but it’s not enough for him so he gets 250