Not the person you replied to, but the only thing on your list with real processing requirements is Jellyfish, if you do transcoding. My pihole uses like 0.3 CPU on a pi4, HA 0.1, zwave2mqtt less than that. You’re more likely to run into bandwidth issues with sonarr/radarr/dropbox, because pi’s just can’t push data to disks very fast, but if you’re doing downloads in the background, maybe that’s no a big deal.