If we're talking hax, not taking into account stats
1. Yhwach (Almighty, Zankai no Tachi, Miracle from absorbing Gerard, almost all the Quincy schrifts, which the SK doesn't have. )
2. Soul King (Almighty gg, Stagnation, Compulsory, Miracle, + Fullbrings and theoretically above Aura level Soul Subjugation )
3. Gremmy (thought based reality warping hax, with stats equal, he'd not run into the problem he had with Kenpachi)
4. Rose (sound based potential death hax which can theoretically hit anyone in stats equal)
5. Toshiro (Power null based on freezing, can freeze massive AOE without even using his special flash freezing ability, has the special flash freezing ability, has a 3+ mile Radius with Tenso Jurin which he can use to power null anything within that area, with his special ability he can freeze all forms of matter including fire and energy, touching him causes you to freeze etc. In a stats equal setting, his ice can freeze large areas before most people can get off most of their abilities. Basically could power null, freeze and kill anyone on the list below him in equal stats or just in hax alone)
6. Mayuri (Has audio based hax like Rose, though his paralyzes rather than potential death haxing, has other paralysis haxes, deadly poison's, a bunch of drugs, a reactive evolution/adaptive Bankai made to counter other powers)
7. Orihime (Without her mindset nerfing her, her offensive capabilities would be equally as potent as her defensive/healing abilities)
8. Azashiro
9. Barragan
10. Gerard (I believe the people or haxes above can find ways to incap him before he get powerful enough to outscale them completely and overwhelm)
11. Aizen w/ Kyoka and Hogyoku
12. Lille
.....too lazy to think about the other 13 to make 25 total in depth, there might be lower people that could be up here. Lloyd Lloyd, Perninda, Jugram, Uryu, Pepe, Askin, Aizen, As Nodt, Urahara, Tosen with his instant incap shikai, his bankai etc, Yumichika's reiatsu absorbing, Rukia's absolute zero, Aura, Yukio, etc would be somewhere around. Probably at the lower end are people that have to hit you to activate their hax like Yama, Gin, Ichibei, Bambi, Tsukishima
Kyoraku is a weird one since his bankai's 3rd act relies on him having higher reiatsu/outlasting his opponent, so idk how that works in stats equalized, and idk if his shikai hax is enough