Ed,
these are interesting issues and it's where tabletop gaming and reality meet(clash). The figure to man ratio of ULB is roughly 1:30. This would make an 18 figures battalion 540 men(a reasonably and realistic figure taking account of paper strength v reality). If you add the extra pike block on to the back of the battalion this may push the actual number of figures up to 24 but the unit would potentially remain as 540 men as I do not count the pike block as extra men: it is a 'combat capability indicator' and aesthetic.
Applying the figure to man ratio to the cavalry each squadron would technically be 6 x 30 = 180 men. No squadrons were this big(even on paper). Average size would be roughly 60 -100 men or 3-5 figures. A three figure squadron would be totally ineffective on the wargames table and have no chance of doing anything. It would also create an artificially high number of command tests. Each 6 figure wargaming squadron is actually equivalent to roughly two 'real life' squadrons. Thus the small English Regiments of Horse(in reality about 200 men) are represented by 1 x 6 figure squadron. A large Imperialist Cuirassier regiment (4 x 6 figure squadrons and anywhere between 720-1000 men strong) would most probably appear like a brigade because defacto it was! Decending one level further, there are instances of squadrons being less than 40 men in reality. This is one figure! and also the point when the wargame itself steps over the boundary of credible illusion into farce.
What must be borne in mind when gaming this period is that the British represented less than 33% of any field army(and often less than that). The vast bulk of Grand Alliance troops were Dutch, Subsidy, German, Imperial or similar. The Imperialists in particular favoured large cavalry units. The French also favoured larger cavalry formations and their Guard and Royal regiments were likely to be far larger than the average English or Dutch regiment.
In summary, cavalry organisation within ULB is constructed to give the right 'feel', maximise playability and speed of execution whilst maintaining the visual aspect of units which at least look like units and not a couple of figures on a base trying their best to look like a regiment
Hope this is useful
cheers
Barry