also at that website you can see if there are existing packages for your brother and fujitsu. do search there.
simple-scan is likely looking for a driver or a plugin/interpreter you don't have installed. invesitgate the tar.gz or rpm packages.
Or see what sane-backends stuff in our own repo might be compatible with these scanners.
use the resource @algent gave you--it's valuable for info.
in the scanner/printer linux world, nothing is instant. all takes a little work
