Very tough decision in my opinion
, I'd probably end up getting rid of either the blue dream or blue widow, even though both of those sound like great strains I think the others in comparison are simply better choices.
If the blue dream was doing noticeably better than the blue widow or vice versa health/plant structure wise I'd most likely take that into account of who I'd toss as well; depending also on your taste for sativa/indica, being a Sativa person myself and the already wide selection of indica dominant strains you have going, I'd probably keep whichever of the two was leaning towards being more of a sativa phenotype.