That's a great assessment.
From my experience, any negative relations makes it virtually impossible to recruit easily or keep a clan for long. And you the moment they join you, you're going to be presented with decisions that cost the relationship. (fief votes, war votes). So I tend to do a little work before I recruit - to ensure I have a relationship buffer of 40 or 50+... so hunt their parties down... catch and release.... catch and release...
Also, be selective. Clans with lots of people/kids with no land are better for you in the long term. They bring potentially 500-700 troops, over that weak clan that almost begs to join with one member under 60 and only one party of 80 troops.
You might also consider their personality traits - I try to avoid clans with too many cruel party leaders - It just starts costing too much to not burn every city you take down, and you'll notice that certain characters constantly try to start wars you don't want, or wars when you're at war.
If you're the leader of the faction, do everything you can to gain influence - work the laws, build forums, build armies and keep only your parties in them. Or more sinisterly, Keep masses of food on you and keep your armies in the field for too long so that the parties run out of food. Do it early, so you don't have to force votes that cost masses of influence later. If you can guarantee 15, 20, 30 or more influence per day, you can keep your clans happy by donating influence to them, and you can win/override votes no matter the cost.
The influence you acquire is much more valuable than the money you spend on clans in the long term.