How cute! The vikings vs samurai thread is still going after what, three years? Anyway:
Urgh. Firstly Mike Loades wasn't drawing the longbow correctly- but that's relatively minor. The longbow shaft wasn't scarfed with oak and had quite a light head- so that throws the analysis again- and finally the range they tested them at would be key- samurai loose shafts at relatively close range. Given the people and the places, this looks like it was produced by the Leeds Royal Armouries in conjunction with the shrine they are twinned with on Japan. Ever since they twinned there's been a lit of Samurai Elite propaganda type material flowing through that place- which is a shame. Approach with salt at the ready...
As I recall from the full program, both the yumi and longbow used in this video had a draw weight of 60 lbs., which is not unreasonable for a yumi, but on the weak side for an English warbow (for a regular longbow, as opposed to "the" longbow, it is fine). That might explain why Mike doesn't have to put his back into it (literally) in order to draw the bow. There is no reason I can think of why they would use such a weak longbow for comparison, except if it was to even the score for the yumi.
How relevant the video is for the topic depends on the parameters of the scenario: is it any which samurai from any which period? If so, the yumi is fine. If we stipulate that the yumi should be contemporary to the vikings, then it is moot. The bows used by early mounted samurai were very weak, and according to Karl Friday (Linky
, p.107) would be used at point blank range (10 meters or less) and aimed carefully at weak points of the armour.
As for viking bows, I really don't know enough about them to comment.