When talking about the 1796/1800 period the demibrigades consisted of 3 equal battalions (after mid 1794 no centre battalion of an old regiment flanked by 2 ex-volunteer battalions anymore).
The battalion had no formal integral light company but probably informal they did. The grenadier company was often detached.
As it is the time of linear warfare, mostly the batalion would be in line, for advance/attack in column formation and the whole battallion could be in skirmish formation.
To portray the more loser formation and give a difference to Austrian/Russian/Brisish army maybe you could make the base bigger (more depth) and put the figures more dispersed on maybe more irregular bases, add "enthousiastic men and officers (waving hats, swords, muskets etc), paint them more campaign look (Eureka do them etc).