To the author, yes this happens in my game.
http://forums.taleworlds.com/index.php/topic,248154.0.html
I just **** them all bad, the starting part is the worse.
Some tips:
(I run my own faction so some of my tactics won't work for you)
1. I would capture any of their weakly defended lands and give them away as a gift to friendly factions I know would not attack me. That way I do not need to defend a place I cannot hold while at the same time weaken them, as they cannot take a land from a faction they are not at war with. If you give the land to a faction not in their clique but nearby them, sometimes if one of them attacks that faction, one of their friend factions in the clique who may be friendly with the faction not in their clique will break the 'hand holding' and go to war instead with its former friends.
2. Your best bet is play defensive at the beginning when they all declare war on you. Learn to smash their individual important lords while marshalling your army. And learn to hold important towns of your own by marshalling your army into it when they bring their host there to siege. Take prisoners (they are all at war with you eventually anyway) and never release them, that way they weaken over time. Don't accept peace offers if you already captured most of the lords especially the ruler.
3. If you are not strong, just play defensive, no need to go on the offense. After a long period of hard fighting , if you smashed some of their lords and if you attack some of their weak lands, they will accept peace offers.
4. For some of the factions, all they have is a town and nothing else. For such cases, at good opportune periods you can starve these settlements out. You need at least 200 men , good troops at that to try this tactic.
Hope this helps.