Read the "that can farm" part. I don't have Barghest and Melusine, my Habetrot still sucks, I don't have Skadi, Koyans, and Oberon, and also the only quick support servant I have (excluding Alexander) is just Nyalter and Wu Zetian. You can say this is not ideal 😉
I tested the level 55 Mélusine against Beast IV, in the Raid, it left me impressed, it managed to cause enormous damage, but it is equipped with the CE of the event.
Well, you can still farm the lower difficulty options. The mid one actually drops the same mats as the hardest one, the hardest one only drops more QP, while all 3 have the same BP.
When I said I can't farm at highest difficulty? Just because I don't have many support servants or demonic beast servants doesn't mean I can't 3T farm the 90++ raid, man. Never assume me like that 😎