By the timing that I like best, there are only a few periods where the timing has you out for more than a few months.
Here is the OUT statistics for 2/1985 to 12/2025:

# of months out   # of times
          1         5
          2         3
          3         5
          4         1
          6         1
          8         1
         12         1
         13         1
         17         1
         18         1

The 18 & 12 is really a 31 month bear market with one whiplash IN month in the middle. 10/2000 to 4/2003. The dot-com bust.
The 17 is the bear market 2/2008 to 6/2009. The financial/bank bust.
The 13 is the 2002 bear market, 2/2022 to 2/2023.

Really, just 3 significant out-of-market periods in 41 years. Hard to make predictions on something that only happened 3 times in 41 years.
You don't need to be perfect, you just need to be Good Enough™

I don't mind not catching the absolute bottom, since I'm sitting cozy in short-term T-bills while waiting for the storm to pass and the sun to come out.

I have a theory why the "overlaps" works so well.
Here's the CAGRs for the number of stocks from 10 to 1:

10   24.5%
9    24.6%
8    25.2%
7    25.8%
6    26.7%

5    27.4%
4    28.6%
3    29.8%
2    31.7%
1    28.7%

Taking the overlaps from the top 5, you are essentially doubling up on some of those top 5 stocks.