7-9 relays should be good.
I have 9 relays.
3 of them are locals
One is Citrine on android
One on my start9 server
One on my mac for when I use nostr on it
Discussion
you have 3 local ones, how?
If you have an android you can download citrine here
https://github.com/greenart7c3/Citrine
Then it runs on your device and you add it to your relay list.
The other one is one start9 server
I connect to it with tor on android and my mac
The other one is on my mac same process as citrine. I will check the name in a few minutes