I’d suggest you choose G-Weezing.
The duel typing will greatly benefit your team. G-Weezing also has access to Heat Wave to hit Opal’s Mawile Super Effectively, unlike Garbodor. G-Weezing will also benefit you later against gym leaders such as Piers and especially Raihan, which Garbodor won’t help with. G-Weezing with either Leviate or Neutralizing Gas will help against Raihan’s Ground attacks or suppressing his weather advantage.
Hope this helped!