With all due respect I'm not sure how many of those Unsung Muslim Heroes are unsung, heroic (beyond the Muslim world) or fall under a historical myth.
Sorry, I mean "heroes" in the more fantastic sense, like olympian hero or the main characters of a fantasy. More in the sense of "larger than life" characters, not so much "people who have sacrificed to change the world". The latter term doesn't work so well, because you can spend lifetimes defending it.
I wouldn't be quick to dismiss them as myth, because history has shown some significant changes during that time period. The only real question is whether it was the act of a few extremely gifted individuals, or the act of many people who have above average skill. From a lot of the documents of that time, it's likely that their heroes stood on the shoulders of giants. There are many narrations of common soldiers going forth into an enemy war camp with full knowledge of what he was fighting for, and that the commanders were dressed in the same gear as the rank-and-file troops. Khalid al-Walid was relieved of his post, ironically to prevent him from being idolized as a hero.
The people the Muslims conquered eventually converted to Islam. That's a sign that they actually respected/revered their 'liberators', but I won't dismiss the whole 'conversion by the sword' theory.
But my rant was more in the sense that if you ask an average Muslim who his most respected figure was, he'd say "Salah al-Din". Not that Saladin was a poor leader, but he had a good advantage, fighting against people unaccustomed to desert warfare, who came from distant countries and were not entirely united. On the other hand, the lesser known Muslim generals actually fought with significant tactical disadvantage, many venturing well beyond territories they were familiar with, and fought against very well trained opponents on their home ground. But unlike the barbarian tribes who have accomplished the same thing, they had a long lasting impact on the world.
I would say it's plenty possible for heroes to be so cross-culturally, since enemies can respect an accomplished and worthy opponent. (That's exactly why the Crusaders respected Saladin, and ancient Greeks respected Persia's Immortals. Not everyone today remembers this, of course -- hence why the movie 300 had to turn the Persians into subhuman monsters -- but it is nevertheless the case.) I don't quite know if there's really a myth that Saladin is the only great Muslim general, but it's certainly the case that his legend has crowded many other equally-worthy figures out of popular imagination, at least in the West.
I think most of us, regardless of cultural background, know about Benjamin Franklin, Julius Caesar, Genghis Khan, Napoleon, etc. But the propaganda changes with time... 70 years ago, the Germans and Japanese were the bad guys. Shortly before that, the whole world was rejecting the British Empire. And then, there was the anti-communism just a few decades back. Today, there's a lot of tension between the Middle East and the West, so it's natural to dismiss the accomplishments of the Middle East.