Working on some giant maggots at the moment

Everything is based in squads, some have 3 or 4 figures on a squad base, some, like these, are based singularly because more won't fit.

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Squad bases are usually 60mm circles with support elements on 60mm or 50mm circles depending on what they are. there are usually 3 squads to a unit (sometimes 2, sometimes 4 or 5 but 3 is usual). The Pardulon figures above will operate in threes and are on 50mm bases because they can destroy armoured vehicles and so count as heavy support elements.
Leaders/Heroes are based on 40mm bases (bigger if needed to fit them). Sometimes they will be based with a henchman/sidekick/partner etc, sometimes singularly.

The Librarian is separate from his Golem because he will ultimately be controlling more than just this one.
Dirty harry operates alone but Starsky and Hutch along with Crocket and Tubbs are based together because they work as pairs. (They should be on 40mm bases but 50mm looked better)

Marsellus Wallace and his gang shown here are a typical force. Three 60mm squad bases of goons (each base has 3 shooting dice), a single 50mm heavy support element (Jules and Vincent, deadly hit men with 4 shooting dice) and Marsellus himself on a 40mm leader base.

three or four groups like this make up an 'army' for game purposes.
I hope that helps to explain the basing conventions a little. Size and function means that a few things will not fit these conventions and so I adapt as necessary but, generally, the above holds true for 90% of my forces.