the only differences i see are the helmets/shields/weapons. i think whos holding what is a bit off though.
i think the spartan helm should go with the axe and round shield.
the backward pointing horn helm with the kite shield and mace.
and the forward pointing horn helm with the square shield and hammer.

Looks good!

Personal opinions:
-The kite shield, as-is, is too clearly 'sectored'; the rest of the character(s) have small regions of light and dark intermixed*, except for that shield- that looks too stark in comparison to everything else. The hammer has a similar issue, and the crested helmet does something similar, but very downplayed in comparison. The net result is that the helmet, hammer, and shield receive far more attention during maintenance than the rest of the warrior's equipment.
-That one metal shoulder adds a touch of rigidity or discipline to the character on the left, which contrasts with his weapon and shield. The fur shoulder on each of the others adds a touch of barbarism to them.
-The forward-pointing horns on the left helmet add a touch of aggression the other two lack.