Yea, a 22k dual element team would probably have trouble. A full water team however, might have been able to handle it.
If you had more water weapons, you should gone all water instead with Melusine (eidolon), Oceanus, Triton, and Nike. Amon might be okay depending on what's actually killing you, if it isn't the debuffs/afflictions, then you can replace her for a R water hime. Though depending on what souls you have available, you could make it easier or harder on yourself by what skills/debuffs you lack, this team is rather lacking in the debuffs, but the elemental advantage might be enough for expert.