But for me it was rather easy, took me 30 minutes to reason between my watches. I simply decided on the situations and chose my favorite watch in each. What would be an impossible question which 3? I too can do 1,6,12,18 or what have you, but three is impossible!
Now the real question which 12? A question for another day. It would be optimal to choose 12 watches that are the very apex of watchmaking instead of my goal of 50 high end. Perhaps I need to rethink my strategy. The Patek minute repeater and JLC meteorite Tourbillon would be easier to acquire....