My ideal stack (for the moment) has become an improved cavalry bodyguard general, 6 or so silver chevron Hospitalers, and the rest gold or silver Border Horse (with upgraded armor and weapon. If I only have the 6 Hospitable Knights then I have to be more carefull in attacking elephants and make sure I stick them in the posterior packyderm place. A pleasant secondary aspect of said army is that it often produces heroic victories, which is what the Scots are all about. (This is a very frugal army.) For fun throw in a unit of any kind of pikes (with secondary weapon removed) and watch the silly AI general charge them straight on with elan. It takes a while, but the pikes will shred the knights and kill three fourths of them before the general is killed and/or the knights route. I have baited the AI general with Border Horse and drawn him near pikes; when he gets near the pikes he'll charge or more wisely sometimes walk over to thrash the peasant pikes. If you have 2 pike units and make a wedge the effect is catastrophic and quick with almost no pike losses.

The Border Horse can easily destroy the heavier Mongol cavalry by using 2 together or in combination with an Hospitaler (or even mailed knights). The trick is to charge the heavier Mongol cavalry in the flank or rear - sometimes repeatedly which is easy usually because the Border Horse are so fast and disengage fast.