Could some experienced player please tell me if this weird idea works?

Grianasteri

Id strongly advise against the option outlined by the OP.

You need magica to do magic based damage and stamina to do stamina based damage. Unless you build a specific hybrid designed to utilise both, then trying to use a 64 mag character to do stamina damage, is going to be pretty gimped. For purely overland content (not dungeons or trials or world bosses), you can probably make it work... but why would you want to?

Just start a new character, there are other classes and races! it really doesn't take that long to level them up, especially if you focus on it and/or use xp scrolls. Even without this its relatively fast, depending on how much you play.