I should have framed my question better as it's confusing- from what I understand...
For complete gamesharing:
- My partner that's in my Family Plan must create their own acct. on the 2nd Switch (makes sense, as if I'm playing the same title = conflict)
- There are licence checks to launch any title which the Primary & Secondary Switch must be chosen but we can always tether our phones, so it's not a bother
- I believe 99% of the MP titles for the Switch require that both Switches to be on an Online Plan to play with each other regardless of our location. This is the annoyance- using the same wifi network won't allow for complete Gamesharing (at least for us to visit each other in Animal Crossing)
I confused "local coop" because inevitably, I'm going to use Tabletop to play with others. But also, with & against my partner's Switch away & local (regardless of location thanks to the online Family Plan). Finally, I was told there's a tool launching alongside 51 Clubgames that assists in the Multiplayer component. I hope that alone solves it. If gamesharing doesn't function similarly to AC, I won't jump in on launch day & will wait for a sale.