Yeah, the current meta is to just axe every lord you come across. The loss in relation with other enemy clans and lords isn't enough (or even relevant to be honest) to the annoyance of having to face an endless horde of low level enemy parties. I understand the game is in early access so i'm not expecting every system to be in place there.
Though, I can tell why TW has come to making things this way: there are so many lords that can host parties that if they were held for much longer than they currently are (that time being basically none), any factions that lost a major battle would have a snowball effect take place that would pretty much just destroy them right then and there. Said snowballing prevention is the same reasoning for why lords can get their party sizes to be so high almost instantly after being defeated.