As always,
Professor T, an interesting thread (even if it is a shameless attempt to maintain your dominance in the all-important likes-per-post league table - which I am sure you realize, your ego just invented for you. Meh, we're all vounteer content providers, if you like collecting merit badges, then go for it

).
I am of the Jungian persuasion, and
ego for Jung is pretty simple: the conscious part of the personality, in whatever shape it happens to be. But whenever somebody draws a diagram of the Jungian psyche, the ego always looks like a very small boat floating on a very big ocean (the unconsciousnesses, personal and collective, that loom so large in Jungian thinking).
So,
sarah_444 called it well, by mentioning "strong ego," as opposed to an obnoxious "big ego." The little boat of consciousness, ego, needs to be strong, to avoid being overwhelmed by the immense forces of the unconscious, or swamped by the enormities of the reality we inhabit. And she is also right that reliable strength has a lot to do with balance.
But, the ideal cannot be the enemy of the necessary. I don't know if you've ever looked at real ego disintegration (sometimes called "psychotic break" or "acute schizophrenia"). It's not anywhere you'd want to go. So, yes, the ego will do what works - tricks, defenses, bristly displays... whatever works in the moment, until (if ever) more durable strategies occur.
There is a great acting gem in
Star Trek: TNG. where the Captain has had some words with Dr Pulaski, and asks Troi to comment. There's an impossible situation: being asked by your boss to comment on your friend, on a matter where both boss and friend are being twits. Of course, Troi rises to the occasion, and observes that "You both have
established personalities." By which she means strong egos, which just at the moment have lapsed into being big egos.
And she's more than diplomatic here, because whether the moment is awkward for her or not, she doesn't want her ship commanded, or her doctoring attended to, by anybody in the grip of psychotic break, or less dramatically, anybody whose ego defenses include running and hiding when reality bites. Better then, to weather the occasional twit storm.
Established personalities... obviously, the phrase has stayed with me all these years.