The funny thing was, if certain characters does not have the weapons they currently do, they would perform either worse or better than they did.

Take example of Zhongli right here. If somehow the lore dictates he's not raining spears, but swords, we'll have a great raw damager with insane shielding and burst-basically, a straight upgrade to Noelle. But if Diluc uses spears instead of greatsword, all we'll have is a somewhat worse Xiao. Same thing with if Sucrose uses Bow instead of Catalyst: she can't knockback enemies while spreading the procs to power her Q. Conversely, Xingqui with catalyst would be even more OP than the current 5* Mona. Razor with sword will lack the current reach and DPS he currently have, and Chongyun with sword instead of greatsword would be a Cyro DPS monster.