Welcome to the blog. I live in Suffolk with 2 Munsterlanders, Bentley who is 6 and Mathilde who is a Blitzan from Summer's litter and she is 21 months old. I used to have a springer spaniel called Wren when I first had Bentley and she was like a mum to him.
As regards crate, I'm a great fan of them but you must make sure you don't treat the crate as a punishment, it should be their safe place. Even though Wren wasn't crate trained she used to get in Bentley's when he wasn't in there to get away from him. Crates help with toilet training, and contains the mess if there are accidents and also gives the adult dog a break from a playful puppy.
I'm also having one of the Eternal puppies, a boy this time. I was thinking of Oscar for a name at some stage. I see you are getting your boy when he is 9 weeks old, is that because you are going on holiday or do you have builders in or something?
Anyway, good luck. Hope to hear from you to see how he is getting on.