Opinions vary about how strong the common factors between to television shows have to be to make them part of a shared single fictional universe or to make one a spin-off of the other.
Some people will accept that two shows are connected with evidence that other people do not think is strong enough.
You may have heard of the Tommy Westphall Universe, a theory that all the television shows connected to St. Elsewhere are part of a the same fictional universe, one that Tommy Westphall might have imagined.
Here is a link to a site that has 441 series linked to St. Elsewhere as of August 2016, less than four years ago:
https://thetommywestphall.wordpress.com/[1]
Here is a link to their master list of 419 shows, 22 fewer than mentioned in the other part:
https://thetommywestphall.wordpress.com/the-master-list/
That list includes Cheers.
Here is a link to their grid of programs:
https://www.dropbox.com/s/ggc0i8xezu29hbu/Crossovers_2016.jpg?dl=0[3]
There is a blue colored cross in the center of the grid, and Cheers is right above the horizontal bar of the cross on the left.
Here is a link to the Crossover Wiki.
https://fictionalcrossover.fandom.com/wiki/Crossover_Wiki[4]
You can search it for Cheers to see their list of crossovers and spin-offs.
I have found another website which has stricter requirements for listing crossovers. It lists only a few more than 100 shows has been crossed over with St. Elsewhere.
http://poobala.com/crossoverlist.html[5]
I'm having trouble getting the link to work, but googling poobala.com or Crossovers and spin-off's master list should bring it up.
This site lists 6 crossover and spin off events for Cheers in the alphabetical list of crossovers by show.
It also has a section of "Crossover and Spin-off Shared Reality Lists" of fictional shared universes in television.
The group 2 in that list includes Cheers and St. Elsewhere and is basically the Tommy Westphail Universe but much smaller,: I counted only 103 shows in that group just now.
For example, the Tommy Westphall Universe list includes all the Star Trek shows, but Group 2 does not. This site lists the shows in the Star Trek franchise in Group 10, along with some rather unexpected shows in other genres.
So you can compare the three sets of Cheers crossovers and spin-offs and see how well they agree, nad decide which shows you think should be on your list.