Like most of the MSQ instanced content this battle's mechanics are more of a review or maybe a quiz at the end of a lesson. The game is essentially saying you should know all of these mechanics before you move beyond this point. Adding a min ilvl might help a little also. Completing job quest at lv 70 as mentioned will get you 6 pieces of ilvl 290 gear and you have access to the ala mihgo 4 man duty you cleared right before it that drops ilvl 300 gear.

I don't see any reason to make this trial easier as the cause of the difficulty falls on players either not wanting to learn battle mechanics or not wanting to gear properly for it.