The problem is not riding a bear in the circus - and actually, you might just be the best bear rider of the world. This is truely an achievement and performance worth praising. The problem is, when you state, that everyone rode bears into battle, and this is the only true way. The problem is having a single piece, and making statistic out of it. In one of his videos, he hints that - for example - he is faster, than Kassai. Again: Nothing is wrong with that. Except for the fact, that Kassai doesn’t do his horse-archery alone, but along with hundreds of other HA’s, involving in an international championship, giving the chance for everyday people to shoot and practice on horseback - and his method is still not traditional in terms of bow usage in war, but - only because of numbers - still more plausible. All in all, it is still a sport.
Believe me, I come from a region really into steppe bows (and ocassionally wild “historical” hypothesises drenched with nationalism, but hey…!), so as you can imagine, he is not the first I see, nor the last who makes a christmas tree out of his bow. Guess how many of them did perform with a composite bow with 80-100 pound draw weight with war arrows. Not even on horse, bigger distance, harder target, with people around them, in combat situation, no. Just proper bows. None, zero, zilch.
But you do not have to listen to me, I am nobody after all. We are talking about “persian/mongol/saracen” warriors? Alright then. Luckily, we have a “mameluke handbook” for example, in which - not surprising - technically none of these elements represent themselves. But even better, on YouTube you’ll find archive footages of mongolian, chinese and korean archers, who do not try to invent a religion out of a book, but actually have a somewhat living archery tradition based on the knowledge of the composite bow. I would love to see, when they will get to know that they all did wrong their archery for a couple of hundred years. : )
And one last thing:
“Here is should be remembers that composite bows used by the different horse archers cultures was not as strong as the english longbows…” - Excuse me, have you ever drawn a properly made, historically plausible composite bow replica, based on hard data? No decent bowyer will make you one under roughly ~70# even if you pay them grand, simply because under this poundage, there is no physical need for the horn layer. A recent conference of the National Archery Association in Hatvan in september, 2014 even agreed on that composite bows with natural material strings might had a pull weight very broadly around 100 pounds. Naturally, I will give you the link if needed, but the presentations do not have english transliterations, so let’s just pretend I didn’t said anything.
Luckily, we do have some acceptable sources in english as well, let me quote only one this time. For example, scythian bows, page 16: “It would be reasonable to estimate the draw weight range of scythian bows to be from 80lb to 140lb, which falls close to a similar estimate for other composites.”
And here is a picture about a knight fighting a snail, if you get what I imply ;]

Naturally, you can release the arrow on the opposite side of the bow, it is a widely known technique. Horse archers shooting with thumb ring often do that, so they can keep a better control of the arrow with their bow holding hand’s thumb finger. …they still didn’t do salto mortales on horseback, though.