Warhammer: Mark of Chaos used the Paper Doll system, and frankly it didn't really amount to much in the form of customized units. You realized that even though you can chance the look of the armor, and build the unit with different delments, colors, and and maybe even so slight facial differences -- it didn't amount to much at all in a satisfactory form of customization.
For in the end, the unit it just too small to really make visible changes. However, if you were to offer the ability to replace that unit with anoither one completely, that offers more of a feeling customization. Even more so if you can change the skin and colors of the unit itself.
So far a lot of the points which aim to de-bunk my idea, don't really have much to them. All I'm hearing is mainly "Too much work" or "Unbalanced". Well the first is for the Dev-Team to decide that, not you -- and secondly, Balance is not an issue when you're just dressing up an already balanced unit with a new model.
XoO Director of Beta Development