Meursault, I don't agree with your analysis of the overlaps. It would be poor in my opinion to have such inconsistency, including an overlap of four letters. It's difficult to specify a linear numerical sequence because the names do not form such. This is what I have, starting with a central pair, then three others in a clockwise loop:
Each name overlaps a predecessor by one letter in this sequence, where there is a break after 2 - 1,2 break, 1,3,4,5. 4 and 5 also overlap others.
There are other ways of detailing it, depending on the sequence of highlighting, but I don't see how one name overlaps another by four letters in any analysis. That leaves two unexplained cells in the tally of 22.
This was one of those puzzles that took me about 90 minutes to fill most of the grid, then another 90 to work out some of misprints/extra letters to get a coherent message and solve the remaining few clues. Indirect definitions made getting some of the letters quite tricky.