Here's where I've come from, and where I'm staggering to, in fits and starts.
At the outset (18 months ago...) I was thinking of 60 x 30 mm bases with a unit per base. Units would have 8 or 9 figures per battalion with 1 standard.
The idea here was to play with the forthcoming Impetus Baroque rules or a variant of Volley and Bayonet.
Then I went off the idea of figures in 2 ranks and went to a single rank of 3 x 40 mm bases with 3 figures on each base. I liked the idea of 120 mm frontage and a thin line. At this point I was still toying with whether to include the Swedish pike in the unit, or to use a special marker stand at the back to indicate the unit had pikes. Cavalry was based 2 figures per 40 mm base.
Well, Impetus Baroque is still nowhere in sight, and is fading from thought. The Maurice rules have now become the preferred option. And so, on to the basing ideas.
Maurice works with any basing system as all movement and range distances are measured in base-widths. Infantry and cavalry units have 4 bases and artillery 1 base.
And so I come to my current options. Units of 120 mm front. First up are 16 figure infantry units in 2 ranks. 2 bases of 30 mm and a central command base of 60 mm. Infantry units would carry 2 flags. Cavalry would be 8 figures on 2 bases of 60 mm. Something like this.
This does go back to figures in 2 ranks which I'm still not sure about, but it looks OK here as a rough idea.
Then there's the option of 12 figure infantry units. Still on a 120 mm front but with figures mounted in a loose staggered line. Cavalry would be 6 or 8 figures. This has the advantage of giving me more units and being easier to base.
Or I could stay with 9 figure infantry and 6 figure cavalry units. I could then just stay with 40 mm bases and play with each unit as 3 bases. The rules work just as well with 3 bases; they just get counted as 4 bases for the unit break-point.
Or I could change from 3 bases of 40 mm to 4 bases of 30 mm and / or 2 bases of 60 mm. Which pretty much gets me back to where I started.
Hopefully if I stare long enough at units and pictures over the next couple of weeks, I'll eventually settle on one option and then just get on with the painting.