I thought the wedges (in my Finds) offered significant arch support, but the two pairs of flat boots did not. What attracted me to the wedges was a reviewer who said she had flat feet and was dependent on her custom orthotics, but found the arch support in these boots comparable.
The other boots' insoles seemed completely flat and I didn't check to see if they could be removed. I have a old pair of Sorel slip-on sneakers whose insoles are removable, though.