I'm not sure there is such a big difference. You wouldn't really say that changing the colour of a soldiers uniform (which a lot of reskins do) really changes the unit graphic much. The mesh, skeletons and animations would be distributed unchanged.
With regards to the legalities I think there is a big gap between the letter of law and what plays out in practice.
For example, Fall from Heaven II uses the Bloodthirster graphic from Relic's Dawn of War for their Hyborem unit. This is technically illegal I'm sure. Looking at ModDB, the latest version of Fall from Heaven II has been downloaded over 100,000 times which I presume is a "substantive infringement" of copyright since they are distributing content from another game for free.
However, it is not really worth companies' time and money going after infringements like this, particularly since that modding is not-for-profit. Imagine Relic went after Kael and the Fall from Heaven team for distributing their graphical content illegally - it would be very bad PR for them in the gaming community at the very least.
However, I do see that DLC changes that landscape. I think trying to have both amazing community created mods while making money out of DLC is like trying to have your cake and eat it. I was indifferent to DLC before, but now I'm beginning to see why it's such a bad move.
I very much disapproved of porting copyrighted content over to CivIV. It just seems so "unmoder-like" to me and I could never take pride in such work. In the case of FFHII, I am sure they will purge the commercial version of the game of any such infringments prior to release. One thing we all have to remember as well is that game companies often have provided us with the means to create our own
orginal 3d content for their games but they seldom have encouraged us to modify theirs with, possibly, the exception of repainting the skin.
However, you are quite correct in that people are starting to learn that DLC and Steam does spell a change for Civ moding and possibly a shift in fanbase marketing strategy. I do not feel that our ingenious moding community will be left alone if they manage to "crack" the system this time..........if they can do it at all to anything that would even approach the extend of CivIV.
I did a little checking and Granny 3d export scripts are available for all versions of 3ds Max after version 4, but they are only available with the Granny 3d SDK which is sold commercially for a rediculous price. It seems 2k Games has gone out of its way to make the 3d graphics inaccessible by creating a special Granny 3d proprietary format.
Although, It does look like there was some intention with Nexus to allow "one-way" moding of 3d graphics, I feel there is interest at Steam/2k Games in seeing if add-on DLC content may be profitable rather than leaving that in the hands of the moding community and it does seem plausible that if one can't make such content, one might buy it if available.
Well, I guess it is a disappointment but what can one do? We bought into it and now we've got it. Then again, it is a little early to close the book on CivV and we could all just be a little too used to the freedom they allowed us with CivIV but I do somehow feel that the "golden age" of Civ moding has ended.