Feel like I need to justify mine at least a little since I made some uncommon picks to say the least (difficulty btw)
S Tier:
Everyone here seems to find Shade, like, really easy. And yeah, I don't find myself losing often, but I usually have to prepare specifically for Shade (not just for ghost types) with certain countermeasures. The only field change that really helps you here is if you can get Misty Terrain up, but even then his pokemon still hit very hard and his Mimikyu stops any attempt at a full sweep.
Adrienne and Aya are doubles leaders, both have bulky, hard hitting teams with good defensive typings that make them very difficult to cut through before they get a few blows in. It can take a few attempts to get a "download" on them and figure out exactly what order you need to do things in to disassemble their teams before they smash yours.
A Tier:
Corey is as high as he is because Skuntank. Like, really, that thing's way more threatening than anything else on his team. Not much can deal with Skuntank "efficiently", especially in the Corrosive Mist field where Aftermath deals a whopping 50%, which is usually enough to kill after whatever damage Skuntank itself deals. Crobat can also sweep frailer teams so if you're using a few too many "late evolution" mons you might just not be able to win.
B Tier:
Serra is pure RNG Hellwith Mirror Field but not much harder than lolnoel without it.
Florinia seems to be on the low end for most people, but for me I find that, while I don't usually get "stumped" or anything trying to win, I have enough trouble on a consistent basis to justify putting her in B at least.
C Tier:
Hardy is pathetically easy with Wide Guard or Rain and just luck without it. His only trick is spamming Rock Slide with fast 'mons in a doubles environment and hoping you flinch.
D Tier: Ribombee 6-0s Noel and can be found literally 10 steps from where you fight him... If that's not "easiest leader" material I don't know what is.
