I'd rather make a push for Doughty or Keith
I don't think Doughty would be seen as a good locker room fit for this team by the astute managerment we have. And are you serious about Keith? He's old and finished offensively plus he's signed forever to a big money deal, a real classic Blackhawks contract when they held out hope for one more Cup. No one is trading for that, the Hawks are going to be a sad sack for awhile. Not that I'd care if I was a fan of a team with 3 recent cups.
I think one of the things GMGM would try to do in an EK65 deal is send off a mid-pair or depth defense as part of this deal. He's already got 7 NHLers signed next year before he figures out what to do with Sbisa, and then we'll see what he does with Brannstrom and Hague. If he can move one of the prospects, and say McNabb, then he's in a better spot to make the deal because he's almost certain to try to work out deals with Schmidt/Theodore/Miller that will go with Karlsson in a fantastic top 4 that's got many good years of hockey in them. Meanwhile such a player traded back to Ottawa would keep their D complete, just nowhere near as good. If you don't think you are going to win for awhile a contract like that is a good way to keep a battle tested veteran who can help with the young players without costing too much.
No I don't want to give up the prospects, but when you think about it that way its sort of a spot where unless you think you will let one of those three guys go now or in the future, you really don't have a top spot for a young guy. The bottom pairing you can always fill with free agents and lesser prospects, or work in a young player who still needs to learn the finer points of covering his own zone which is what Hague likely is. We'll see what else Ottawa insists on if Ryan has to be part of this deal.