>>49602301
>They have no discipline
How do you explain fairy maids then? Besides, you don't need sustainable front-line to be held, using fairies and not going for irregular warfare consisting of is a waste of their skills. You just need to keep them coherent for small engagements.
>no drive for sustained conflict
True, but they have a yearning for fun in their very nature. Making them equate fighting your enemy with fun is a matter of presentation.
>limited problem-solving skills
Not necessarily true, after all pranks are standard for all fairies, while some of them are quite devious. Groups of more simple-minded fairies executing plans and orders of officer-like smarter fairy could work.