It's not a workaround.
In the old days, if you had 2 services that were hard coded to use the same network port, you would need virtualization or a different server and make sure the networking for those is correct.

Network ports allow multiple services to use the same network adapter as a port is like a "sub" address.
Docker being able to remap host network ports to containers ports is a huge feature.
If a container doesn't need to be accessed outside of the docker network, you don't need to expose the port.

The only way to have multiple services on the same port is to use either a load balancer (for multiple instances of the same service) or an application-aware reverse proxy (like nginx, haproxy, caddy etc for web things, I'm sure there are other application-aware reverse proxies).

Holy shit I totally thought I was talking out of my arse lol

Yeah, you and I have very similar use cases with this. Gluetun, VPN, download clients + *arr stack, I get it. I'll be sure to update with a solution, if I spot one (when I get around to looking)!

I just set up vpns in my router and use macvlan network for my dockers so I can route their individual ip addresses to whichever interface I want...

Yeah i pretty much stole this from someone else, although it only used a single torrent client so i just added another that looked the same. i'm not very skilled in docker, so some things may not be best practice (or even correct)

qbittorrent:
    image: lscr.io/linuxserver/qbittorrent:latest
    container_name: qbittorrent
    network_mode: service:gluetun
    environment:
      - PUID=${APPUSER_PUID}
      - PGID=${APPUSER_PGID}
      - TZ=${TIME_ZONE_VALUE}
      - WEBUI_PORT=8084
    volumes:
      - ${PATH_TO_DATA}/qbit/config:/config
      - ${PATH_TO_COMPLETE}:/downloads
    restart: unless-stopped
    depends_on:
      - gluetun

  qbittorrentTL:
    image: lscr.io/linuxserver/qbittorrent:latest
    container_name: qbittorrentTL
    network_mode: service:gluetun
    environment:
      - PUID=${APPUSER_PUID}
      - PGID=${APPUSER_PGID}
      - TZ=${TIME_ZONE_VALUE}
      - WEBUI_PORT=8085
    volumes:
      - ${PATH_TO_DATA}/qbitTL/config:/config
      - ${PATH_TO_COMPLETE}:/downloads
    restart: unless-stopped
    depends_on:
      - gluetun

  gluetun:
    image: qmcgaw/gluetun
    container_name: gluetun
    networks:
      pirate_net:
    cap_add:
      - NET_ADMIN
      - SYS_MODULE
    environment:
      - VPN_SERVICE_PROVIDER=protonvpn
      - OPENVPN_USER=[USER]
      - OPENVPN_PASSWORD=[PASSWORD]
      - SERVER_COUNTRIES=[COUNTRIES]
      - VPN_PORT_FORWARDING=on
      - UPDATER_PERIOD=6h
    ports:
      - 8084:8084 # Qbit
      - 8085:8085 # QbitTL
      - 6881:6881
      - 6881:6881/udp
      - 8191:8191 # Flaresolverr
      - 9696:9696 # Prowlarr
      - 7878:7878 # Radarr
      - 8989:8989 # Sonarr
    volumes:
      - ${PATH_TO_DATA}/gluetun/config:/config

networks:
  pirate_net:
    driver: bridge