You can all play on the same server, and even join the same alliance. What you can't do is feed each other resources or work together militarily. I know...it sucks sometimes not being able to help each other out, but if we enforce this rule, then we take away 90% of the reasons people have to multi-account and almost all of the ways they abuse having those multi-accounts. It makes everyone's lives a little easier and the game much more fair.