A very thorough response, Marybob, thank you for spending the time to write that 
You make perfect sense to me.
I atually really wish there was a better way to recruit for an Alliance inside the actual game - or a better way to filter through all the, is the term, ghost Alliances. It´s hard to find the right match, I imagine. On both sides.
I´m currently in an Alliance, where 15-20 members rarely participate in Titans. Around 4-7 members sign in for War, but do not partipate either. Very little communication. Yet it is difficult to leave, when one is as loyal as I am - it was really not my intention when I joined, but…Yeah.
Yes, I sometimes really have to be active as soon as a War begins, so I can cherrypick teams that match my own, as you say, going up against 4k teams is not super motivating, when you´re new!
I often experience people joining the Alliance, without saying so much as a word, and then just staying for weeks, without any kind of interacting. But I guess all the “no cups required, free to enter” scenario is the cause of that.
I imagine all those powerful Alliances must be with people that have played this game for years already, so it makes sense they want to gain more out of it. 
Again, best of luck to you - maybe I will find my way to Hogun’s Hero Academy some day in the future 