The logic is that Ragnok doesn't want to piss off his king buddy, because the king has more men, ships, money, and power, than either Ragnok or that other guy. The king is being a dick, yes, but Ragnok dealt with that the best he could. He straight up told the guy, "Look, it's not me that doesn't want you on the raid, it's that douche of a king". While it was a shitty move on Ragnok's part, He really had no choice; if he would have told the king no he would have lost a powerful ally and gained a lesser ally. Not a smart move.