A couple of years ago I built a spreadsheet for TSATF factors using 2d6 for all of the morale tests (simply because I think it gives a better distribution when you are adding and subtracting 1's).
Troops are initially classified as European or Native Regulars, or as Irregulars who normally fight by Charging / Shooting / Skirmishing. These gave the base 2d6 morale scores for each of "standard" troops of these classes. For example Skirmishing troops would be less likely to "Stand and Fight" than Shooting Troops.
I then thought up a few "Attributes": Confident, Fanatical, Fierce, Rash, Timid and Unsteady. I gave each of these plusses and minuses for the various morale tests. This allows you to allocate some racial stereotypes (and what could be more Victorian than that?) to vary units. So I'd class Ansar as Fanatical Charging troops. For Beja I might add Aggressive. I'd class Jihadiyya as Fanatical Shooting (or Skirmishing) troops.
Egyptian Troops might be Unsteady Native Regulars, and Gendarmerie would get further penalised as being Timid in addition!
For standard TSATF games it's just another way of varying the existing factors, but with a bit more faux rigour. However it's a useful way of rating troops that are not in the TSATF canon.
So do your lizardmen charge hard, or do they snipe from cover? Do they melt away at the first sign of opposition? Do the stand solid in their primitive defences? Do they ignore casualties? You can allocate scores to each of these variations as you like. And it's a fun exercise to think through how the psychology of each troop type should work on the table.