Musing development team can implement functionality to look for similar questions that are already in the database. before posting they could give suggestions about if the question is already asked and answered. more than 70% match with an existing question can trigger a repeat alert also.
they can also add filters to possible repeats and merge them auto or a moderator could do that.
there is no moderation at this point they could introduce moderation as well.
Rewards can be adjusted to give more rewards to unique and valueable questions