I also use miniatures in 15mm. To depict forces i have two stands of figs per unit and use counters to record the hits. To distinguish lights i base them in skirmish order 4 to a base or put them as 8 figs per base as line.
I also use the hexon 2 transitions hexes this allows for the base layer to be arranged so that there is no need to mark the zone changes just use a different terrain. ie desert transition L flank, green centre, transition R flank.
If we are having a quick game then i use either the C&C board or the battlelore extended board (for breakthrough scenarios). And play with single stand units on the 50mm hexes. see pics below.