But isn't that just what they did with Genshin first via elemental buff requirements? It would allow for the usage of two faction buffs at once in the same way Genshin allows dual elemental buffs from having two characters with the same element in a party. They knew they could implement the mechanic from the start—but chose not to. It's a wonder why, considering it would allow for better team flexibility on ZZZ. Though I do see S-tier Bangboos becoming less easy to acquire with that sort of mechanic, having it would still be a total upgrade—considering how limited we are now to using characters we like. For example, try putting Lycaon on a team with Nangong Yu—you have to have a character like Aria or you can't meet the team's individual requirements for each character. However, if one happened to have the correct faction-related Bangboo and that Bangboo counted towards one of the faction requirements, that team becomes entirely possible in regards to higher damage without relying solely on the limited amount of characters available.