in the altaic family languages are come from same ancestors i think they are (chinese,korean,japanese,uralic) and (native american, turkic languages.)
and later group of O(Chinese) - N(Uralic) relationship with tibetan peoples. tibet and mongol peoples more earlier than us. and also they have language.
and when O - N relationship with them their language change and effected by from tibet language. and also turkic/native american language effected by mongol peoples.
so this is why today we cant healtly contact with that all languages.
mongol/turkic is working but in the origin they going be different.
also chinese/japanese/korean/uralic turkic/native american they all have common ancestor and language in the before times.
and i think sumerians(language) are isolated language from proto altaic ancestors. maybe they go mountains to north
today we can good contact with (chinese/japanese/korean/tibet and turkic/mongolian but we cant add group of all this family together because their effected by earlier asian two peoples and languages(tibet,mongol)
if there is no have mongol or tibet peoples. we can doing healthly contact together with all of them languages. (also origin, and words)