Slitherine

I am in 43 and have three Russian guard units on the map (from the Siberian reinforcements). I should be able to have 9, but the "Elite" button is always grayed out. Is there a trick I don't know of?

Thanks for any help.

It means you're playing with the option purchase Russian guards off (default off). That means you get guards instead automatically via promotions. When a Russian land unit gets 35 or more XP they're promoted to guards (up to a yearly max).