Joseph
Where did you get the notion that there is a limited amount of olam haba that has to bed divide up?
Even if there isnt enough olam haba to go around and it must be divide up,why cant we leave that to the ribono shel olam?
While on the subject though, my rebbe R’ Shurkin (a talmid of R’ Moshe) would often say you get double schar for eating chalav stam: for keeping kosher and for listening to the pesak of a gadol.