In reply to George.D:
The Hochtouren series by Daniel Silbernagel is very good. But, the Oberland and Valais books are out of print until summer 2020.
Although in German, the books rely largely on topos and map extracts and have an English introduction that explains how to use the book.
I have the Graubunden book in This series and it's fine to use without reading German. All the essentials are in the topo.
I've been looking for an alternative. The SAC guidebooks look terrible. And nothing else looks good enough.
I've decided to wait for a reprint of the Silbernagel books.