Thank you to all who have taken the time to respond. The 23mm lens I have is the f1.4. In terms of what I shoot, it is a mix and I use the Fuji X-T1 and Canon 5d mk3 about equally. My X-T1 is my preferred travel camera, and my 5D mk3 is my wildlife camera (with the 100-400 mk2 lens). I like landscapes and architectural, and do get asked to photograph people and events, though rarely large groups (I was asked to do a formal, not action, group of 12 bellringers last week). I do not do weddings! With people I do not like to get too close as I think they can be more natural if I am further away, hence my liking for the Fuji 56mm f1.2. I do not do candid, and am not really attracted to street photography, though open to persuasion. I do not want to emulate Martin Parr, but that is just me. I am starting to put people in my landscapes, as they can give a sense of scale and I like to put people in a context.
I did discuss the 23mm lens question with a friend last Saturday at a party. He loves his Fuji 10-24, and does use it for landscapes. He thinks it enables him to get foreground and skies. I am not convinced as to me it may make the main subject less obvious, particularly if the foreground, middle ground and sky make up 1/3 each (I was taught not to put a horizon across the middle).
My purpose in asking the question was to see if I am missing something that would broaden my approach and take me out of my comfort zone by using a lens I already have.