[Gwathagor]

The dwarves would absolutely be at a disadvantage in the open 1) because there were fewer of them and so could be surrounded and 2) because the elves had archers. Darn good ones, too.

Legolas is described by Tolkien as being and tall and strong as a young tree, able to string a Great Bow of Lorien with ease. That hardly sounds "frail and rustic." I mean...rustic maybe (Thranduil did wear a crown of forest flora) but frail, not at all. If anything, their forest life would have made them tough and resilient.