changing the custom-selection menu?

Does anyone know how to change the faction assigned to slot 2 on the faction-selection screen in custom battles? (and, no, making the faction non-playable in custom battles does not do the trick)

Rome.LNT does not seem to hold the answer either, though I may be wrong.

?

You could re-arrange the positioning of the buttons for each faction using Rome.lnt (by changing their x,y coords), but that's a purely aesthetic solution (i.e. if you use the next/previous buttons they'll still be in their default order).