While the faction creator is alright in WoM it would be really cool if we had more control over the visual aspect of our factions. Here are some changes I would like to see to it.
1. Sliding bar for unit height and girth. Every faction in the game shouldn't have the same body build. If we want to create a race of dwarves or half-ogres it should be possible. Just being able to change the scale of the model is all it would take.
2. Skin color palette. Many of the Fallen have different skin colors. It is hard to differentiate a new faction if they have to look exactly like an existing one. Being able to change the skin color of factions to create a race of desert dwelling men or sickly grey Trogs would help players create interesting new factions.
3. Lasting Fashion. While many factions have unique clothing it doesn't really matter once they start wearing armor. It would be cool if factions had several unique items that could be worn over armor. Simple things like spikes, fur, feathers, fins, or manes that could be added to helmets would do. Tabards, turbines, shoulder pads, and skirts would also allow units to stand out and help players stay interested in their units. None of these items would do anything stat wise, they would simply be little personal touches players can add to spice up the looks of their units.