I seriously doubt that they will or can. Seriously, you can’t stop people ditching an alliance unless they start coding that information into player profiles. If there is something I can complain about, you can be sure I will, but my experience is that things are fairly reasonably balanced until you have 5 straight wins.
My personal war score has been driven up from its starting level of around 1813 to yesterdays level of 2063 after 4 victories and the defense teams i have been facing have gone from ~3600 to this one just gone at 3980 (my defense team is 3585 pts and I have just one attack team over 3650) and so they did have 3 strong attack teams and 3 mediocre ones, wiping the floor with me (but they had to use all 6 flags to do it) although i can put up a variety of 8 plus different teams (albeit weaker). As a consequence my war score has fallen accordingly and my next war should be a winnable matchup. It is simply not realistic to consistently win time after time and expect that your opponents are going to be totally onboard with losing time after time.
Maybe you should be looking at peoples rosters, using known strategies and improving weaker players skills?
I don’t think you can force people to follow the rules and I am fairly certain that alliances that manipulate their matchups are a fairly small minority. Most people are interested in fair play in my experience.