Well to be honest I would.
I've always been a fan of Max, and chose him over Hampshire but Shaul's involvement shows us what we are missing too.
Organising the defense and giving energy to the team is vital and is the flaw in Jowitt's game
In terms of confidence under the high ball and backing up through the middle, I'm not sure there's many better than Max in Super League.
So I'd only replace if it was a top notch player, but I would if we found one. (Or at least keep Max as backup if he was OK with that.

Don't forget Max's kick's goals and for me that's massive getting the extra 2 over, Shaul has been good and there's nothing wrong with having 2 good FB in the squad.

I agree on both.

In terms of Shaul I really like him.
I'm thinking contract might be big though and he doesn't seem to have his blistering pace back yet.

Same I’d keep Jowitt. He’s about to hit his prime years soon and Shaul has 5 years experience on him which is likely where most full backs would develop their game reading/ directing defence and players. Max has a lot of good attributes and these next 3-5 years are when he will start to grow his game further and guide the line like Shaul does. Max shows glimpses of being able to sort the line out and appears to be working on this part of his game. I would trust we will see the best of Max if we keep the faith in him to keep growing.