Thunder_Gr
Emperor
What annoys me is that once you can upgrade to Champions (or any variation thereof) and Rathas, you can no longer build Radiant Guards.
The only solution I've find to this is to simply never get any horse resource, thus being unable to ever build Rathas, but still able to build both Champions and Radiant Guards.
You can have a city/some cities without a barracks, so that you will not be able to build a champion there, but still build Radiant Guards and Rathas. Then just move your RG to a city with a barracks and upgrade.