[egri]

I think it depends on the set. I would consider a T206 set complete even without Wagner, Magie, Doyle NY NAT’L, and Plank, because of the extreme rarity of those cards. Same with a 1933 Goudey set sans Lajoie; it wasn’t issued until the following year and has a 1934 design. OTOH, the 1952 Topps high numbers are expensive, not rare. I don’t know enough about the other sets the OP mentioned to weigh in specifically on them. The gray area for me is where to draw the line on rare vs. extremely rare, but I guess that’s a different topic.