@Achillius: The position is that when the rule book says 'look at the model', the model they are referring to is the official GW model, not the model on the table. If this is the case, certain instances of modeling (axes on DCA) are not WYSIWYG because the rulebook/codex doesn't allow for those models to have power axes.
Now, reasonable people can disagree with that position. But that position is manifestly not the position that you can't convert models. It is the position that, by RAW, DCA can only have Power Weapons. If you want your DCA to use Ork bodies, Eldar heads, IG legs, and Daggers from some other game company, and your opponents can tell what they're supposed to be, I'm sure Battlegrounds is fine with that. But if you model them with axes, that is a problem, just like if you model all of your Space Marines with lascannons, that's a problem. The codex doesn't allow them to all have lascannons, and the codex doesn't allow DCA to have axes (at least according to the position taken above, which, again, reasonable people can disagree with).
Perhaps we can split this conversation off to another thread? I have actual rules questions I want to ask without them getting lost:)