I don't think having a current shardblade will have anything to do with founding the orders of KR because of Syl's reaction to the blades. Something is flawed with the blades as we saw in Dalinar's flashback when the light seemed to go out of both the plate and blades. The "something" needs to be restored and the new KR must "build" their own way. I think Dalinar is intended to be the new overarching leader of the KR, just as Noadon (sp) was the guiding light to the knights of the past through "The Way of Kings", they need an organizing leader, not just ten different heads, but one person to look up to and rally around.