Some rules (Beneath the Lilly Banner) seem to have a different representation for horse and foot.
This is an easy fix and also cheaper...
However, there is another solution.. depth.
I need to put 5 cavalry (125) in a frontage of (125/3 =) 41 mm .
40mm figures are 12mm wide ....no go.
I then thought of the Swedish arrowhead formation for horse.
This allows the arrangement of figures to overlap if they are arranged in depth. If each figure tucks in behind the previous one by a couple of milimetres then it is possible to fit 5 figures inside a front of 41 - or 45.
45 can be used if we allow that cavalry will not actually manage to stay boot to boot the whole way in and gives us a practical leeway for setting the figures on the base. We have already decided that the infantry will have 45mm so this will match nicely .. for the tightest cavalry formation.
But what about the depth ? The arrowhead means the 5 cavalry figures are 45mm wide but 90mm deep !
Looks like a problem.. but is it ? If we consider the infantry have a depth of 60mm for their two ranks is 90mm so odd? 6 ranks of foot will be about 3 to 6 metres deep. 3 ranks of horse will be 6 to 9 metres deep. (depths taken from Napoleonic drill). In true scale this means 6mm and 9mm respectively !
If we look at the proportionate 'flank' of a foot or horse formation to true scale we can see that the 'flank' is almost non-existent.
The actual result of a flank attack is a progressive series of -surprise - attacks in the rear of the line's sub-units. The idea that one of the line's sub-units can a) turn and b) stem the attack while their comrades do something , is a non-starter. If you examine the relative widths of a unit advancing down a flank of a line you can see the impossibility of this.
Otherwise it is slaughtered.
This means.... that the depth representation is not really crucial if we make the rules in relation to flank attacks realistic with reference to the reality of how relatively thin battle formations actually are.
I can now return to model the bases thus :
SHOCK cavalry 45mm front with 5 men in arrowhead.
LINE cavalry - must be broader than arrowhead to acknowledge tightness of that formation 3men 50mm wide with 2 in the second rank.
The different types of cavalry can now be distinguished easily and the units really look like they mean business!