An all out attack on the Roenall's keep isn't something a noble or otherwise goodly alligned character isn't likely to do, not only due to the general cost of life, but the fact that you'd be killing a whole family over what boils down to a blood feud. However, that kind of thing would be pretty fun do to. To get good aligned characters to the Roenall's keep, why not have the Roenalls invite you to their keep to go to a feast or some such as a peace offering? While they're there, it could be an ambush, or conversation might turn nasty or you might even decide to go there and attack anyway.
Looking back at it, it's the kind of thing that anyone should be able to smell a mile off, but it's just a thought.