Hey since nobody answered you I'll give it a shot.
Your code looks right, except that the default value is horde in the initial code and alliance in yours, but that shouldn't really matter.
It might be the case, that visual studio is unable to to understand the needed order to compile.
That means: If you rightclick your sollution and just create the whole sollution it will try to create each subporject at a time. If your changes to m_team are in a subproject that is compiled after your posted code, then this error might pop up.
So the best way would be to compile the subprojects in order, or at least the one with your enum at first and then the whole sollution afterwards.
I hope that was understandable. >_<
Intellisense might have been updated even if the binaries are still the old uncompiled ones.