if i were in your shoes, i would put jellyfin on the machine with the fastest cpu for media transcoding. Your nas doesnt need to be the best machine, but i would make it a dedicated as a nas. Everything else can go on one machine with a good amount of ram. I would separate your homelab with your “production” server, so youre not goofing around on hardware that is hosting services you rely on. You have enough machines to setup high availability and mirror your production server it goes down.