if this is the case, the fight without tension would be boring
Tension is with how good Mihawk truly is, just like the first fight. Zoro thought he was good enough only to realize he was still too far. If this can be replicated, I'll enjoy it. Zoro being top tier for the second duel only to realize Mihawk is still on another level, this is good enough tension for me.
Zoro's life, dream, and promise to Kuina is what's at stake as has always been. If the first one isn't boring, then the second also isn't gonna be boring.
Zoro's own story don't really need any worldy things at stake, that's what already Luffy is for. Zoro's meaning in the bigger scheme of things is just to be a fighter for whatever Luffy stands for. He doesn't need to be more than this.