I believe so. The bit where Harshnag(?) gives them the main quest. Instead Blagothkus can be that link. Especially as he might owe them a favor if they liberate his castle. I had the dragon cult hold his wife’s spirit hostage in order to get Blagothkus to comply with their demands.
Just finished reading through ROT and SKT over the weekend. I think that will work, assuming Blagothkus survives the end of HODQ But even if he doesn't, I think I can have Harshnag show up to one of the Council Meetings or maybe have the Council send the party to find him to link in.
I also think I'll change up the Oracle part of SKT to have them do the Stone, Frost, and Fire giant castles.