It would be hilarious if Hegar didn't make the runoff.
It being TX, that is entirely possible. I think it will most likely be 2 out of 3 of Hegar, Tzintzun-Ramirez, and West. But Hegar might not necessarily by one of the 2. Each candidate has different bases (and pretty much all of them overlap with some of the other candidates also):
Hegar - establishment vote & White suburbanites, probably some Austin-area regional support
Tzintzun-Ramirez - progressive vote and Hispanics
West - DFW vote and African Americans
What about Bell, I guess that Bell would get some older voters that remember his 2006 run and know only him since the field is horrible.