hacon: Thanks for the info. I've seen that article before. It's very interesting, although naturally it involves quite a lot of speculation.
"Spartan Rangers" is a generic term used to describe the forces they used for light infantry, scouting battlefields, and so on. In the classical period they used the Sciritae for that, but I'm guessing that they replaced them with other troops for the same role after they lost Sciritis.
Zarax: I think we could easily lose the Krypteia entirely - I can't remember the last time I recruited any. Still "more Spartan units" is one of the most common requests we get.