You do remember that most of them are kind of dead, right? It'd be hard to interact with a dead person unless you yourself are dead. I'd rather avoid past connections with known characters, since I want Trunks' recruits to be about raw as it could possibly be, but I doubt a previous acquaintance with Yajirobe is gonna break the game so I'd be willing to make an exception with that one.

Also, how recluse are you talking? He'd have to come out of hiding to join Trunks' team at least otherwise the RP might be kind of boring from your point of view.

I need to make one more note about Namekians. Dragon Clan members are extinct. That means no new Dragon Balls for Earth, which means death is very much permanent and therefore something you don't want to make light of... especially given the current apocalyptic state of the world right now.