I've proved in the past (https://www.youtube.com/watch?v=cQLiANnRPBU) I can get plenty of traction with a minimal game done by a couple of guys. Moreover, since the RTS is competitive, I can get a feedback and growth loop by organizing tournament with prizes. If the core gameplay works and the updates are substancial, players will come more and more numerous each time.

Here is a video of the RTS (January): https://www.youtube.com/watch?v=fNIFd6jxQbY