They're various auxilia units; some are from RTR and some are from Roma Mod.

On the topic of formations, though, I think that the width of individual units has to be taken into formation. A three-man-deep, skirmisher spaced, 160 man formation just does not work in the game. The guys won't skirmish; they'll pivot around until someone runs over them.

So unit depth as well as unit size need to be considered when making formations. 'Cause if they're spaced properly in one unit size they won't be in the others and so forth.