On the Bakerloo/DC line - I could see in future that the WCML slows become much more of a stopping line, to Tring - once HS2 opens and the WCML fasts see most trains call at Watford, MKC and Rugby. And many more at Leighton Buzzard, Bletchley (by then a thriving interchange).
That same speculative and optimistic future might see a new Bakerloo (new trains, extended to Hayes, many more TPH) - which could see services call at Queens Park again (a very busy station) - possibly Willesden Junction (I would not do fast line platforms though) - and more at Wembley Central with works to enable it to be open and safe all day without manual access.
On those lines, it would go something like:
2tph Clapham Junction - Watford Junction
6tph Euston - Tring (skip patterns south of Watford Junction - but each pattern to include 2-3 of QP, WiJ, WC, H&W, Bushey)
2tph Euston - Bletchley/MKC (Harrow, Watford, all stations)
(Hemel and Berko removed from outer services to Northampton/Brum and to go more metro in nature)