I would like to see a heavier statement about Mohammed in tarot cards, and also a few other prophets, but it just doesn't seem to ever work out that way. I imagine Mohammed to have a strong statement on the Moon card, but it seems that either nobody knows what he looks like or nobody wants to paint him. Mohammed was the great prophet who conquered, and was referred to in the Old Testament along with the one who the world would mourn for. You know a prophet is true when the prophecy comes to pass. Jesus said that for those who fail to keep watch, when he returns he will come as a thief. This means that upon his return he will seem as a villain to those who are ignorant of the scriptures, too comfortable in their complacence. This unfortunately includes the very people who still bewail the first coming, little do they know He already came twice.
There were a number of great prophets from the past century of various levels of influence, and these are the guys whose messages never seem to get reflected in tarot decks. Of course a great many of the prophets' messages overlap, so they do influence the cards however indirectly. The guy who sits on the watchtower has a duty to report what he sees. The vast majority will most likely ignore their fair warning, but the messenger is the one at fault if he fails to deliver it. Much of the Apocalypse of St. John has already come to pass, mostly within the last 100 years. The mythology of our time is the place to look.