I don’t know Document scanner, but Vuescan is using it’s own libraries to handle scanner hardware, regardless of SANE installed or not. Vuescan happily works with scanners SANE does not support.
GIMP on Linux needs Xsane and SANE be installed, otherwise it won’t scan. On Windows, I guess it uses Twain interface.
So install xsane, that will bring sane as a dependency too. And then you’ll see the “device dialog” menu in GIMP.
Another question is that if SANE supports your scanner? If not, you will read in Xsane, that there’s no scanner found, or similar.