I think you can just delay the Searing Light until after bahamut. This issue should resolve itself at 86 due to the new Garuda and ifrit abilities which will fill that gap. It could also be that you have slightly too much SS (Though given you are still levelling, not sure this can be the case). I find When Raiding Savage that Searing Light coms off cooldown just before Bahamut comes up. You could also off set Searing Light by adding a cast in the opener.

I currently use R3+Searinglight > R3> Bahamut and that sets me up for nice alignment throughout the encounter unless i goof it up (which is usually the case)