Put me down as skeptical too. The 180# in the vid was 'Estimated" The ones they tested to 30" was 34 kilos....76#.
I doubt the archers in those days were coming to a full 30" DL....
In the vid they said they found bowstings..... but none were capable of anything like 180#.
If they were really experts they would be able to tell by the arrow spine as its crucial in a bow with no cutout. They have 2,000 arrows....easy to test and see what they spine out at.
Or it could be like a couple of the guys I've sen at Trad tourneys bragging "I shoot a 70# longbow"...but then they don't come anywhere near full draw.
Edit; I'm looking at this wrong. The heavy bow guys weren't shooting MOA accuracy.....and poor arrow flight from the bow would correct itself at the 200-400yd distances they were raining these arrows down. Its not out of the question to think there were guys capable of shooting them....as in those days they wanted a heavy arrow thrown as far as possible.
I was surprised to learn [from some 100# longbow guys] that once you get up into that 100+ bow range, sure they shoot logs, but spine wasn't as finnaky as I would have guessed. They say bow efficiency drops for longbows at those heavy weights.
Come to full draw with a 70# longbow....28" or in my case 30". It doable if you train a little bit. Speculating here but coming to full draw with 160# that last 3"-4" would be tough. Even if you train, I'm a pretty big guy, decent strength in my youth....and I bet I could have pulled a 160# bow ....to MAYBE 24".....no way I'm holding it at full draw -30"- and aiming.