Of course, Shakaru should have to give consent. We'll see about that offer...
I don't see why he should have to consent to it, at all. As far as he's concerned, if the debt gets sold, he owes the same amount of money to a different person.
That is a point of view ... mine is that getting everyone to agree on the deal is
probably a lot better for everyone's general happiness in the long run.
Certainly having his consent won't hurt general satisfaction, and it's nice of you to wait for it, but even if he was vehemently against the deal, he shouldn't have a say in it.