Robin or Tribbie?

I know there have been a lot of these posts. My first team right now is THerta, Aventurine, Servel, Sunday and my second team is some form of Lingsha, herta/himiko, HMC, flex.

I know I have some other characters I can build up (March 8, Pela, Moze etc) and I am hoping to pull for Castorice down the road. In the meantime I have about 8k Jade and trying to decide on whether to try and get Robin or wait for Tribbie? Open to any advice