"You might want to use your 3 melee combo, that way you'll have access to verflare/verholy and scorch".

I'd write this and totally move on.

Came across a very similar situation where a SMN was using Garuda against bosses. All I said was: "You might want to use Ifrit against bosses", as to what they answered with a silent "ok".

Guess what? They started using Ifrit on bosses.