Either we cultivate more realm-team spirit, or acknowledge to new players before they join that there is a lot of politics and whatnot that sometimes create teams apart from the realm-team.
My problem is that if I were a new player, nothing is meaningful to me, and I wouldn't have any interest in teams within realms. Killing other people with your team has a more of universal appeal.
From a slightly different direction, these politics are generally irritating asides to those not involved and with no stake, and new players by definition have no investment.