Although their involvement wasn't big enough to merit their involvement as a single faction, any chance we could see some of the Greek Legion? Perhaps just have them as an individual unit under the Russian roster.
It would just be cool to have them since they look so unique with their fustanella, caps, and bright colors:
While I don't think there is anything unique you could do with them in terms of stats, there is something you could perhaps do mechanically. From what I see in paintings, the Greeks tend to love to cram their sashes with all matter of stuff, including multiple pistols. Along with a rifle and ammo you could randomize the infantry equipment (they are described as havings staves, pistols and daggers). To mix things up Maybe give the officer a unique saber, and two pistols? It would make for an interesting change of pace, being able to basically double-tap your enemies, shooting with one pistol, then drawing the other and shooting again, something I haven't seen done yet in a NW mod.
Although not from the Crimean war, this basically illustrates what I am getting at
Anyways, probably not a priority, but just something to consider for the sake of flavor. There's not much information on these guys, but this thread seems a good point of sources:
http://www.victorianwars.com/viewtopic.php?f=11&t=10632