Chmrr > VUX
The Chmmr can take major damage, at least if it's not careful.
Melnorme > Umgah
A skilled or lucky Umgah that reverses right next to the Melnorme can do serious damage. Melnorme can't really stop that strategy.
Supox > Zoq-Fot-Pik
This battle is pretty even. The Supox doesn't even have an advantage.
Syreen > Ilwrath
The Syreen is big and doesn't have particularly good acceleration. Ilwrath are very good at gravity whipping.
Thraddash > Ilwrath
Thraddash > VUX
Yeah, if you have infinite patience.
Utwig > Chmrr
Chmmr can slam Utwig into the planet, or fake Utwig out, or hit it with the tip of its laser when it's not ready. None of these are easy, but Utwig is definitely at high risk in this matchup.
Druuge against Yehat or Utwig.
From what I hear, it's pretty easy for Druuge to fake Utwig out.
Androsynth>Chmmr
Spathi>Kohr-Ah
Chenjesu>Druuge
Everyone>Illwrath
Everyone>Umgah
You've been playing the AI. Chmmr can avoid bubbles easily, Druuge can avoid DOGIs easily and don't sacrifice crew constantly if they're human, Ilwrath can gravity-whip, have high acceleration, and tend to beat Earthlings even without that, and Umgah's backwards movement is easier to use than you give it credit for.
There's literally nothing that has a guaranteed win against a human-controlled Chmmr Avatar (or at least, against an Elvish Pillager-controlled Chmmr Avatar.)