This is getting pretty nuanced, but I think this is the sort of situation where our college counselors would be OK with doing more than just 2-3 applications in a given selectivity range.
Like, I think a very common reason to do more than that in our HS is if the kid is potentially interested in both stand-alone liberal arts colleges and also the liberal arts colleges that are part of private research universities. There are a lot of overlapping values between such colleges, but also some differences, and it is at least possible that a given kid will do a little better with admissions in one or the other, even if the generic admissions stats seem similar.
OK, so a kid like that might, say, apply to 4-5 colleges with similar selectivity, some LACs, and some private research universities. Which is fine.
But that logic has limits. Like, our counselors would likely still say you should really be careful about choosing a range of LACs by selectivity. Same with the private research universities. And you should still watch the overall application count so you can do only very good applications.
So, maybe you end up with 3 likelies (one very likely public university, one likely LAC, one likely private research university). Then a mix of 4-5 LAC/private university “targets”, and a mix of 4-5 “reaches”.
That is still only 11-13 total, so that’s fine. And it is still a well-balanced list, meaning you have many chances at getting into at least one exciting opportunity that is different from your very likely public university.
This is just an example, but the point is you can be very deliberate about all this, and different people will end up doing different things. But rarely is a top-down, rankings-based, shotgun approach going to be a particularly thoughtful optimization strategy.