I agree that Karlach's resolution one way or another should be earlier in the dock scene, fylimar. Good call!
I created this thread after reloading the ending of my first playthrough to see if anything obvious had changed, and the ordering went:
- Lae'zel (whom I'd earlier failed to convince to abandon Vlaakith) tried to kill Orpheus and my character stabbed her to stop her.
- My Tav killed herself rather than live as a mindflayer.
- Then Karlach went up in flames.
I'll admit I almost appreciated the OTT Shakespearan-tragedy impact of it all, but it would have been good to have the potential to persuade Karlach to fight on. Or at least not to have my Tav's grand sacrifice upstaged by Karlach's so much cooler death scene coming straight after!