Psyringe: I haven't played them myself yet, but
and [url=http://www.gamersgate.com/DD-GOG/guardians-of-graxia]Guardians of Graxiamight be worth a look. The latter seems to be card-based though.
Also, if you can handle the complexity of oldschool boardgame rules, I cannot recommend
Blood Bowl enough.
Guardians of Graxia has the whole "move units around a board" bit though. The game is interesting, but sadly held back by the incredibly slow speed that units move at. And you can't skip these if you want to have a good overview of what is happening during the AI's turn (there is an option for skipping them in the options menu). Also, the way the AI moves things is far from time optimal, which makes things even worse. If you can live with those things though, then there is an interesting game.
There is a board game using the same ruleset that looks quite interesting though.
I've heard that Legio is a pretty crummy game, but I've not played it myself, so I can't confirm that.
Oh, and Blood Bowl, that game is great! Not super similar, still very good.
amok: isn't it basically FF: Tactics, Valkyrie Chronicles, Tactics Ogre, Disgaea et.al extensions from this kind of gameplay?
I have not played the later ones you listed, but FF tactics is not all that similar to Dark Legions. They are all tactical games, but FF tactics feels more similar to something like say Chaos Gate than Dark Legions.
Actually, come to think of it. Take a look at Birthright: The Gorgon's Alliance. There is a mode there were you just play battles, and skip the whole map campaign.
http://www.mobygames.com/game/birthright-the-gorgons-alliance