If it's the Moon Knight mesh that I'm thinking of, you see "melee," "melee_2," and "melee_knife," correct?
If you look in the character tool, you will see "_a," "_b," "_c," etc. for all of the animations, giving Moon Knight many different animations, but since there are only three distinctions ("melee," "melee_2," and "melee_knife"), those are the only three that you will see, but the game will use the variant animations randomly when the character uses that specific melee attack.
If you'd like to make each melee attack its own animation (not a variant), the easiest way would be to rename the animation into something else, like "melee_a" to "melee_3" (since there is already a "melee_2").
There is not need to copy branches; just rename the animations. That should get them to work for you.