when did we compete against elves in the Olympics? And in many settings elves are physical strength is the same - take DnD the main elf god is androgynous and dark elves females are physically stronger then men (thanks to loth)
Honestly, I think an all female army has a lot more interesting cultural implications than an all male army simply because our culture tends to act like “male = strong, protector, provider, and female = fragile, nurturer, submissive.” We’ve seen all male armies, we’ve seen co-ed armies, all female armies are less heard of, and the idea of women being the strong protectors is refreshing for some of us.