I really don't get the nubians. They're slightly better than vanilla spears, but not exactly comparable - better morale and attack with worse defence (due to their "small" shield). This basically means that their only task to be imagined is anti cavalry. They simply cannot stand against infantry. This fact makes them quite useless, as there's no reason to not bring Muwahids instead of Nubians if you're looking for a flank cover unit.

If, on the other hand, they would have had a "large" shield, they'd essentially been "disciplined" FSs. That would have made a lot of sense. The Eggs would then have had a little bit of tactical flexibility for desert fighting that their arch nemesis - the Turks - lack. Basically, that flexibility would be the only thing resembling an advantage for the Early era vs. the Turks. Much needed, indeed, but inexplicably overlooked.

As it stands, the Nubians are utterly redundant as either main body or flank cover due to the more streamlined Muwahids and SIs. Therefore I take it upon myself to edit their shield to "large", which just gives them a function as opposed to none whatsoever.