Symmetry breaking

Meet Allen Marshall and Marshall Allen.

Allen's a good person. Not perfect, but well above average. He's got a good life. Again, not perfect, but well above average. Allen knows this comes from holding A above all else. The same holds, for the most part, for Marshall. The main differences are that Marshall's good fruits come from holding M above all else, and he knows that the standard of A that allows Allen to be a good person with a good life will, eventually, run out of steam, whereas Marshall's own standard of M won't. Allen feels similarly, except he knows that M will eventually fail.

This is sad on two counts, the first being that Allen and Marshall are friends, so Allen would much prefer that Marshall realize he's headed down a dead end before running into it face-first (and vice-versa) and the second being that by holding himself to the higher standard of M, Allen would still end up meeting his original, lower standard of A as well. At least, so Marshall claims. Allen, in turn, knows that Marshall would still get M by putting in the extra work to meet the higher standard of A.

Alas, nothing Allen says or does seems to make this point. Allen's got a good life, but it's not good enough to persuade Marshall that A is more important than M. Allen's a good person, but Marshall says that's despite Allen holding A above M, not because of it, and so isn't an indicator that Allen's right. Allen may hope that Marshall will come to accept the importance of A, but as time goes on, there's less and less evidence that it'll happen. Nor does Marshall have it any better, as all of his evidence is just as unconvincing to Allen.

With such a fundamental disparity, are there any worthwhile grounds on which Allen and Marshall can be friends in a meaningful sense, or is "friendly acquaintance" the best that can be hoped for? What range of things might they be able to both improve upon together, from their separate starting points? How broad is the range of things that are between A and M which can only be reached from the 'higher' one, and not the 'lower'?

If there's a yet-'higher' standard Q which, if it were followed, would subsume both A and M, what are the chances of either Allen or Marshall being able to become aware of it? Are their chances at all improved if they have access to each other?