My questions are:
1. What DM is giving out both of these items in one campaign?
2. Assuming there’s a good reason for these items both being awarded in a single campaign, what party is not sharing these items between two spellcasters?
To be fair, these questions are not really relevant to the question at hand, and they side-step the rules-question. It may not be likely that both weapons are discovered by a party in a single campaign, or given to the same player, but both things are totally possible.