You could have 2 totally diff. pheno types wich then there wouldnt be much u could do to change the growth... the one might grow short and have more of an indica trait were the other could be taller and take more of a sativa trait.... you can always top her... that will keep it smaller. Like im growing some seedsman blueberry... and 2 of the 3 are identical in size and growth. But then the 1 other 1 is substantially bigger and just a total diff growth pattern... all had the same nutes same environment everything the same ...