Indeed, for current events elemental advantage and PF carries more than enough for damage checks. The true cuck comes during tower and AQ5 if I know what I’m reading in the DMM wiki however, the tower has the last boss with basically wind rag levels of debuff resistance, and you’re somehow expected to burst through that with as mediocre a nuker element as water. As for AQ5, with your elemental advantage I’d much rather just take the hit than try to burst through a normal and a rage gauge in 7 turns without Asherah.
Would additionally like to note that I find Cthulhu especially redundant in the “perfect water team meta” currently: you have Hercules covering a 25% def break, a free Atalanta that covers the C frame already, and a Ryu-Oh that covers the A frame atk break and has BP, leaving with only the orb reduction that doesn’t land half the time.