Selene is not always better than Eos. Why do I say this?
Selene can actually lower DPS on combo-heavy classes like Monk. She can also cause issue for White Mages who spit out more heals quicker than expected.
The best faerie to use is the one you've tested. Yes, that is vague. Yes, it's on purpose. Neither faerie is best in all circumstances. Likewise, no scholar heal is the best heal for all situations. You have a tool chest from which to draw, not a checklist to follow.
And frankly, I would not use Selene with the intention of her healing being superior to Eos. It is not. However, Selene can help YOUR healing. However, you have to really be cognizant of the fact that your faerie effects more than your stats, healing, etc.
