I think only melee classes are having such a problem, especially othell.
I don't want to offend you also, but by mid gear it is more like +15 elmore cloak, 5 slot boorch with 4 lvl jewels, 7 sign, abundance 4, evolved Taurus agathion, R110 Krishna bloody weapon 450 element, blessed antharas/valaks, lindvior, rulers ring of authority, Olympiad ring, dragon shirt, Noble or Radiant Circlet of Authority +5, level 105+++ etc etc
For FAFURION + Prelude of war updates this is considered LOW TO MID GEAR if you have seen the progress in korea/eu/ru servers, in general people have better overall gear and lvl 5/6 brooch jewels, which is a crazy boost.
If we had the chance of getting gear freely somehow and 3 times cheaper store like other zones do, you would have wiped this instance and probably never ever do it again, since it
does not give a lot of xp as I heard from others.
I am also 100% sure you can do this instance, few practice runs and will be fine!