I'm glad to have read the comments of several people on this thread, since I've recently started a campaign with Egypt on High/Hard, and have been considering whether or not to include Muwahids in my army.

My only experience with them comes from an earlier Almohad campaign, in which I found them rather unimpressive. Of course, this was because I expected them to act more like traditional spear units, and instead found them getting repeatedly thumped by cavalry in head-on fights. There were simply too few of them, they lost their cohesion too quickly, and they were too vulnerable, both in melee and to arrow fire. Nevertheless, I continued to include them in my armies, mostly because the only other spear unit the Almohads have is the lackluster Nubian spearmen. When playing as the Turks, or presently as the Egyptians, I've stuck to the much more solid Saracens almost exclusively for spear infantry.

Now, I remember reading in the unit guide that Muwahids were fast on their feet, and that this made them better for flanking, particularly against cavalry. This sounds reasonable, and is obviously the way I should have been using them as the Almohands. Nevertheless, I may prefer camels for this task, since they have better bonuses against horsemen. Of course, camels have serious weaknesses as well - they are weak in head-on fights, vulnerable to missiles, and weak in trees. Muwahids share these weaknesses, but camels have them even more so. I suppose it could go either way.

Ultimately, I think that Muwahids are a little too specialized for my taste. They can flank, but not as quickly as cavalry, and cavalry is useful for other tasks as well. They may have great morale, but how useful is that when they simply can't win their assigned fight? They will lose to other spearmen, being outnumbered, and they will get cut up by swordsmen. As I've said before, they can't even take on horsemen from the front effectively, especially if the horsemen are heavily armed and armoured (and not too tired).

Even if Muwahids are great at the one task of flanking cavalry, that's just not enough for me. The Turks and the Egyptians both have excellent cavalry for guarding the flanks of their armies, which are more geared towards mounted units anyway. For both the Turks and the Egyptians, Muwahids are superfluous.