What do you mean no deterrence? She pulls out a giant glaive from out of nowhere and people are going to stop the rush and consider what that means. It is an absolute deterrence and in my opinion a better one in that case. Merely because they don't see the heavy polearm at the beginning of the fight, doesn't mean us pulling it out is not going to be a deterrence.
Theory never makes it into practice. If that was the case, then every city guardsmen would be a noble, and that isn't the case. Being a cultivator sets you apart from the mortal realm, but that doesn't mean we are nobles.
We have become a cultivator and so we have new expectations that are being placed upon us, and those expectations are to act in a more noble manner and perform actions with grace and poise, but that does not make us a noble.
I also believe that you are placing too much weight on the nobility of the Jian. Meizhen, Cai, and Sun are all using different weapons than a Jian. Meizhen has a metal whip type thing, Cai has a rapier, and Sun uses a spear. Even Zihao isn't using a jian and he is the son of the Royal Guard's Captain