While I laughed at Bombur when first reading
The Hobbit, I was impressed even then at how he, and all the other dwarves, turned from merchants into ferocious fighters at the Battle of Five Armies:
Out leapt the King under the Mountain, and his companions followed him.
Hood and cloak were gone; they were in shining armour, and red light
leapt from their eyes. In the gloom the great dwarf gleamed like gold in a
dying fire....Wolf and rider fell or fled before them.
Go Bombur!
I was also impressed that there was armour among the hoard that could fit such a fat dwarf.