A former neighbor had over 100 varieties planted nextdoor, and had a farm out of state (in the Appalachians, if memory serves) with almost 200 (with some overlap vs the nextdoor orchard). He had a buddy between here and there who had a farm and was growing over 350 varieties. The estimated number of varieties (some of which may very well be extinct) is over 3000 I think.
Wow. Just........wow. I’m only on 1.2 acres and in the South, so I just opted for those three trees which were self-pollinating but were good cross-pollinators with each other. We also have a dwarf Elberta peach, nectarine, and late red peach that are of the same aspects, and a Keiffer pear tree. The peach and nectarine trees are beginning to fruit, but between the tree rats and the occasional late frost, we’ve only gotten morsels s far. We did plant four Northland blueberry bushes between a row of roses along the side of the house. We’re keeping an eye on them because they actually produced about a pint of berries while still potted last year, and we noticed a good growth spurt from them this spring.