I apologize, I do not follow sumo wrestling at all and mentioned that I was only assuming and basing my theories on the video alone.
The rest of my info came from his wikipedia page which more or less sounded like he couldn't compete very well at the highest level (makuuchi):
Takanoyama had a difficult start to his makuuchi career, losing his first five matches and then only winning the sixth when his opponent inadvertently stepped out of the ring first (isamiashi). However, he picked up a legitimate win on Day 7, downing the 166 kg Yoshiazuma with a hooking inner thigh throw (kakenage) and instantly becoming a favourite with the tournament crowd.[7] He finished on 5-10, which sent him back to jūryō in November, but he responded with a 9-6 record which returned him immediately to the top division for the January 2012 tournament. He was unable to produce a kachi-koshi score in either January or March**, but in the May tournament he managed an 11-4 record in jūryō which earned him a 2nd place and a return to the Makuuchi division in the July tournament. However he had yet to earn a winning record in five tournaments in makuuchi and was demoted to jūryō once again for November. His 7–8 record in July 2013 was his seventh consecutive losing score, pushing him towards the bottom of the jūryō division. In September 2013, he finished on 5-10, his weakest performance in jūryō so far, which sent him back to makushita 2 for the November tournament. Afterwards, he skirted the border between the two divisions, being relegated twice and promoted twice
Like I said, I do not follow sumo wrestling at all and thought the divisions were comparable to the likes of College Football vs the NFL (again using NFL analogies since we've established a trend). You could have some amazing College Football players like Tim Tebow, Robert Griffin, Carson Palmer, etc that all won the Heisman Trophy (top college player of the year) that the end up not being even close to to the top player of their position in the NFL.
The top 40 wasn't something I was sure in judging since I had no idea how large the talent pool was for sumo wrestling.