I currently have 9 razors that are shave ready and in my rotation, but seem to keep adding more...
I have a LOT of blades that I am in the process of restoring (probably about 25 in various stages from rusted and damaged to only in need of honing) and will add some into the mix as they are finished and sell or give away the rest.
Out of the ones I currently use, two are wedges or quarter grinds and the rest are full hollow. Three are 6/8 or larger and the rest are 5/8. There is no pattern or rhyme or reason to my collection, I just picked up razors that I liked
As for choosing the razor on an given day...thebigspender nailed it!