I did a PD collection of Wilfred Owen’s poetry for Standard Ebooks if you’re interested in reading it: https://standardebooks.org/ebooks/wilfred-owen/poetry

A Siegfried Sassoon collection is on my list, but I haven’t got around to it yet.

I don't know how well Sassoon's poetry has worn. But his George Sherston novels--Memoirs of a Fox-Hunting Man, Memoirs of an Infantry Officer, and Sherston's Progress--are very readable.

[edit: corrected spelling of "worn".]

A bit more than "camaraderie" - they were almost certainly in a romantic relationship, whether or not it was physically consummated.