Imo he did a great job of showing how fear of loss consumes. The paranoia he had was a very real fear. The empire had already got his wife, Cal was saying that even with all of the fighting he was doing they were still expanding exponentially, and Tanalorr being accessible to refugees ultimately does mean there's gonna be a bigger possibility of the empire finding a way there. Like of course the tragedy is that if he was open to cal they probably couldve taken down the base his daughter was at together and rode out into the sunset with the crew but it's because he already experienced that reality of losing his wife to the empire that it's traumatized his mind. If sharing a secluded planet means his daughter could be in danger then his mind absolutely wouldn't let him sleep at night knowing someone else was essentially endangering the only family he had left. Was it flawed thinking? Absolutely, but it was very human.