One problem was the huge difference in their lances. I normally replace spears, pikes and lances with brass wire but plain wire doesn't look much like a late-medieval / renaissance lance, even with the blobs of epoxy that had seemed OK as a hand guard when I painted my old unit of gendarmes. Eventually I found a fairly quick and effective way of making replacement lances with brass wire and Milliput. I posted a how to for this some while ago on the Miniatures Page and will re-post it on here at some point - it is quite easy and nothing like as fiddly as it sounds. The end-result isn't perfect but they don't bend, and are better proportioned than the chubby telegraph poles cast on some figures. Most importantly it gives enough of a uniform appearance to allow figures from different manufacturers to be mixed without looking ridiculous.
Part way through painting these, whilst looking for inspiration in contemporary illustrations and on some the excellent blogs of 28mm Italian Wars miniatures, I noticed that the rider's skirts weren't quite right, being too small and not covering the back of the saddle so I modified the later ones with Milliput.