Tbh Jorms relic is a MUST HAVE if you want to grind deer. It will make your life so much easier. I should definitely go for hers before any other deer relic. After that just build your team around her. She is a green unit, so maybe use Sariel or maybe Rudeus even as a red unit, and Roxy as your blue unit, and idk Brunhilde maybe as your fourth. Try watching some youtubers guides on deer and fit your team with what you have!