Yeah,open weight contests are driven by the idea of that you don't choose opponents,opponents choose you.And its probably an optical illusion,Yamashita was shorter than the other guy so it seemed like he weighed a lot more.I just love how Yamashita tripped the guy into newaza and the throw at 0:51 going into newaza.Betcha both of those setups would have been an ippon in today's olympics...
If judo alredy gives all the tools for ground fighting, why would I need to train Bjj? If all I need is train more Newaza. Judo also defends better against takedowns and, in my opinion is better even for self defense, because, if i can perform a good throw on an agressor, I woudn't even need to fight in the ground, once the impact against a hard ground may be enough to knock it out.