I think the idea is pretty solid, but they would need to remove a limit per members to guild spar (or increase it?). For example, if Heaven decides to take the tower from Alumni, they could guild spar with 10 members while Alumni only have 5 members at the tower. If it's just 5vs5 max, then it would be too easy for top sparring guilds to control it for long and I would understand that players do not support this.