Well. you could do that. but think about this for a second.
By the geometry, each race has two elements closest to it. Those could be the boosts, which works for Dvarves (Hammer, Axe), but takes away Archery as a special for Elves.
But again, it's your game, and you're the one who has to implement it. I'd say just keep in mind the game might expand, so even if you build the function for 1 elemental boost and 1 class boost, do it in a way that scales, so if you do want to expand later, it's easy.
two boosts, one for class and one for element definitely works.
@DukaZhou Character models finished (unanimated, though). Left is a human with an axe, middle is a female elf with a staff, and right is an unidne with a polearm.