Most of Stevenson's characters are all the same (4,2)
I believe the answer is:
even so
'are all the same' is the definition.
(I've seen this in another clue)
'most of stevenson's characters' is the wordplay.
'EVEN SO' is hidden in amongst the letters.
However, I'm not sure how this is indicated.
Can you help me to learn more?
(Other definitions for even so that I've seen before include "'Nonetheless (4,2)'" , "however" , "'Despite, still (4,2)'" , "Notwithstanding" , "Just the same, though that may be the case" .)