I imagine not much, because he isn't making any outlandish claims. He is doing, by his own claim, "exhibition shooting" meaning trick shooting. He's doing some very precise skill trickshots and doing them extremely well. He's not claiming to have rediscovered some long lost art, or that his shooting is the One True Way(tm).

In particular you'll notice that he is shooting at targets thrown more or less straight up at a reasonably close distance, presumably of his choosing. Between an amazing innate ability and presumably tons of practice, he can pull off amazing shots. However he's not claiming he can do it from horseback, or that ancient archers did this shit all the time.

He claims to be a top notch exhibition shooter that can hit virtually anything you throw, and indeed he is and can.

I have much more experience than the average person. Lars seems to invent and conjecture as much historical evidence as some other posters here, but what he does is very impressive. You could accurately classify it as trick shooting, but since archery is now a sport instead of a practical thing...it's all pretty gray.

What's neat is that Lars' technique works significantly better than current common practices...albeit in what are currently uncommon situations, such as riding horseback or running & shooting. There are 2 things that makes these kinds of situations difficult:

1) Keeping the arrow resting against the side of the bow and the handle. If you've ever shot before, most beginning shooters will have their arrow accidentally drop to the ground many times before they fire a successful shot. Even for someone who is more than a novice, a strong breeze can easily knock your arrow away from this notch. Shooting while on horseback or running is a whole new level of difficult.

2) Firing rapidly. Firing off many arrows in succession is a difficult thing, seriously. Despite Anna Maltese's dismissal of Lars' demonstration on why firing on the 'wrong' side of the bow is faster, it truly does remove many of the steps, and speeds up the entire process. In modern archery, Right handed people fire the arrow on the left side of the bow, and left handed people fire the arrow on the Right side of the bow. Reasons for this could be conjectured, but from personal experience, learning how to shoot the arrow from the wrong side of the bow is almost like learning archery all over again...it feels weird. From watching related videos, the way Lars holds many arrows in his hand, making sure to rotate each arrow into the appropriate knocked position each time, is a significant achievement that Anna did not touch on.

What's particularly impressive is that Lars has achieved improvements in both categories simultaneously by firing from the wrong side of the bow. To my knowledge, modern trick shooting is the typical shooting style simply with impressive feats of accuracy, or at best being able to throw an object into the air and hit it with one arrow. In comparison, Lars changed the way he shoots his arrows, and has been able to significantly upgrade the art because of it (throwing an object in the air and hitting it with 3 arrows before reaching the ground). In my opinion, this is beyond regular trick shooting, and warrants a reinvestigation on why modern archery is the way it is.

Out of interest, does anyone here have any expertise in archery?

I certainly don't, and my lay opinion of Lars was that it looked like "trick shooting".