Vaalingrade
Legend
Priority: Immediate threat, quick pursuit vs disengagement.The party has a Fighter who is up in the BBEG's grill, getting ready to hit him hard. Based on previous rounds, it may be hard enough to drop the BBEG.
Priority: Legendary Resistance Exists, so this threat doesn't.The party has a wizard who the BBEG has seen cast a lot of spells but not his top tier spell.
Priority: Immediate Threat, range may hinder pursuit.The party has a rogue who is sniping from behind cover, and a successful hit is more or less just as likely as the fighter's hit to take the BBEG down.
Priority: Absolutely zero. Oh no, someone might not die.The party has a cleric who the BBEG knows has spent all of their big magic and could potentially yo-yo a fallen character but not do any significant healing.
So yeah, in this case, geek the fighter.