1. Presentation is mostly related to forum or map section presentation, bb code etc.
2. Object Data is mostly related to synergy between models and concept in general, to make it simple, take this example:
Some Human Race
-> Militia, Swordsman, Knight, Paladin all with human (let's say all have blue) icons and textures and so on. This would be good way.
Some Human Race 2
-> Militia, Swordsman, Dragon, Warlock Mage, first 2 have swords, 3rd one use red textures and is freaking dragon, while warlock as well don't fit here.