It's possible to mod new units in BE. The reason you don't see new unit models is the exact opposite of the problem you have. Which is the people that know the code are probably not knowlegeable about how to do 3d modeling or they aren't good at art like me.

In fact I've been experimenting where I did add UU for my sponsor mod, which its T2 unit is a slightly altered 3d model of the soldier unit without the oxygen tank that is working in game.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=496580461
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=496580579

However I'm not an artist I can only collage. So I can make my 2d leader look different from the leaders that I used parts from. Though you do need to know the xml coding at least to get the model in the game. You could however team up with someone that knows the code and they could write the code to create your model into a unit in game, or try learning it yourself.

Also modder don't talk much on the steam forums its better to look at civfanactics forum for learning how to mod Civ 5 or BE, although the BE side of things is quiet. http://forums.civfanatics.com/forumdisplay.php?f=394

okay, I see what you mean. I mean, I'd be happy to work with others

sim