Don
I really like that little set too!
I have about 8 of the 5972 sets, but I also have 4 of the 5978 and 2 of the 5240 to round out the Blue Axe force.
I bought a unit of 9 Red/Yellow Fleur de Lis foot Knigts on E-Bay, and have added 6 4762 Archers to support the Red/Yellow Fleur De Lis Force. But, Sad to say the canons that come we these sets really will not be much help knocking them over in a 'Little wars' game sense.
Warhammer is a great system, and that would really work well, you will have to double or triple the ranges. Warhammer 40k does have scatter dice. Also WOT came up with a set of rules a while back called 'Melee Combat', that I was helping play test. They are easy and fun to play.
Good luck with your battles, please post some pictures.
David