Modding is a lonely road. On the other hand, almost all the group projects we have heard about over the years faded to vaporware, and the only work that actually ever gets done is work by lone modders.
If you're having trouble a lot of trouble, you might consider scaling back your plans to something which:
a) you definitely are able to accomplish based on your current skill and knowledge level, and
b) you will most likely be able to accomplish given the available time you have to work on the project.
These are good guidelines for everyone making any kind of mod for any game.
There aren't many guys working in this genre these days, and all of them have their own projects keeping them busy. Don't hesitate to ask questions when you need help, but putting together a group to help you probably won't succeed. If you have specific, well-defined tasks you need help with that's one thing, but "help me make some maps" or "help me design good battles" are things every modder has to figure out for himself.
You may also want to rethink your release strategy. Releasing a bunch of tiles isn't very interesting to most people. Maybe try making a demo of your mod, with one or two fully playable and well-polished maps, to generate interest in your project. Then work on the rest later.
