Well, you have two LMB SSR Eidolons, so your HP pool is still fairly low. Once you have six, then you should easily be able to heal for the cap regardless of Hime.
honestly, once you pull SSR eidolons to where they give more than an event one, they aren't a scam... unless it's strictly character attack with either burst damage up or ability damage up. those character attack ones are situational...
there's a rare instance where I might stick Huanglong in a main slot (if i somehow need the HP), but MLB echidna is the 2nd highest fire elemental boost and the highest dark elemental boost in the game right now... how is that a scam?
it's luck oriented sure, but when you get the elemental atk eidolons going, two or three of your teams is covered until you (hopefully) get a 100% eidolon. those gacha ones go up to 50% (tri element) or 60% (dual element). most you get from ANY event eidolon is 50% (and that requires a full eidolon deck matching it's element) with the next closest being 45%.
then add on the fact that to overtake something like a lv100 echidna, you need to have both belial AND the 100% dark eidolon we don't have yet... otherwise your echidna still has use somewhere.
i'm not saying by any means to rush out and go gacha crazy. but what I am saying is that if you get one of those elemental gacha eidolons, it's not bad unless you have one that's stronger in all the areas they cover...
but i can agree that the character attack ones could be a scam. those need specific setups to really work