That is correct. But you are talking about de professional sumo championship in Japan, The Makkuchi Divison of sumo. The rest of the world gets to fight in the Amateur Championships. In those champiopships sumo as 'evolved' because the matches are influenced by wrestlers that practice others MA such as Judo, Sambo, BJJ, and others. Thats is why amateur sumo is very strong in takedowns. Where is a link for more information: http://amateursumo.com/