Chelenga is 23 and has 5 years of physical maturity advantage over German, so it's not an equivalent comparison. Nonetheless, I think German will be in the battle.
What's scary about German is that he is a better track than XC runner...yet he is still winning races at cross country. Just imagine what this lad can do during outdoors. Given 4 years of injury free training at progressively higher training loads, this kid can go sub 13 as a collegiate runner. This is the next step in NCAA distance running evolution... to have sub 13 5000m times run at collegiate races.