Dain had in the book a five hundred elite dwarves veterans from the War of the Dwarves and Orcs. As it is written in the book:
The hobbit book Chapter 16, A Thief in the Night:
"I thought as much. i see I have some information you have not got. Dain, I may tell you, is now less than two days march off, and has at least five hundred grim dwarves with him - a good many of them have had experience in the dreadful dwarf and goblin wars, of which you have no doubt heard. When they arrive there my be serious trouble."
I love your elite unit for Iron Hills from book. But all dwarves from Iron Hills looks like a elite veterans from book? Dwarven in the movie looks more like regular army. I think it would be nice if Iron Hills have a bigger difference between the regular army and the elite.
I think that would be a nice compromise like this:
1) Three basic units with design from movie
2) elite unit with design from book
So, everyone will be satisfied. What do you think about this idea?