This is only a rough estimate i believe but i found what doom eternal has a possibility of looking like on switch.
At 720p 30fps id assume 4GB of ram would be fine with the proper optimizations.
Ive expirenced this setup first hand and can say its around the same as a nintendo switch. It can run pretty much every recent game on low settings execept warzone and apex legends. Apex i assume is going to have optimizations.
i think this is about a general idea of how it will run on switch. I have a feeling that the maximum supported resolution will be 720 docked or not. However we cant be sure until we finally see gameplay of it. (Hopefully it launches with ancient gods part 1)