I find Clarks run 1/2 size too large (they're long).
I always wore 7 wide - but recently purchased Clarks Medora Elie and Medora Ally in 6-1/2 wide. Perfect fit.
I also purchased Clarks Medora Gemma ---- 2 pairs in 7 wide (a tad long) and 2 pairs in 6-1/2 wide. So I wear thicker socks with the 7 wide -- and thinner socks with the 6-1/2 wide.
All these shoes are "closed". With open backs, the sizing may not be as obvious.