Yes, I agree with you and your husband: a Lesser Spotted Woodpecker can appear greater than in actually is, when feeding in a woodpecker-like manner on a tree and appear smaller, when searching for insects like a Tit.
I allways thought, the reason for this might be a comparison in jizz-ID at the first split-second our brain is making (all other black/white woodpeckers are roughly similar sized, so the brain is doing some auto-correction)
Same with the slightly smaller Middle Spotted Woodpecker: when I immediatly see its one, I can see, that its slightly smaller than a Great Spotted Woodpecker and when I see just a woodpecker, than I think its about Great Spotted Woodpecker size.
And thanks Butty for your patience, that judging size in a lone bird is often unreliable. After reading this multiple times here, I had a oppurtinity to check this out with a Greenshank, a Wood Sandpier and a Temmincks Stint yesterday. You are right, thank you!