Just realized I missed Mandalorians when I read through other people's posts. That would be insane. Getting to field units of Mandalorians.
I think the Star Wars Miniatures by Wizards of The Coast had Mandalorians as their own faction, but it was from Old Republic Era. No need to restrict yourself to timelines for game purposes though. Just have Vader fight Maul and have the victor fight the Rancor. You know, for fun.
However the new Jon Favreau show is supposed to be focused on Mandalorians, plus we already have the stuff with Sabine Wren, Fenn Rau and Gar Saxon from Rebels as a starting point.
For example here's a Mandalorian on a Basilisk War Droid. How insane would that be?