I feel we've already seen the perfect solution to this scenario.

The Shadowbringers finale, when our character was staggering toward Emet Selch. That was perfect - rather than standing there listening to him monologue at us the WoL staggers slowly toward Emet Selch whilst everyone else (i.e the Scions) engage him in combat.
It's also of note that said scene demonstrates that it doesn't have to be the Warrior of Light who acts first.