Playing with linux permissions

I have a shared folder, that I synchronize with unison (ssh) that I want to allow for read-write for 2 users, that unfortunately were not created in the same group

I choose the following solution so that I don't have to bother which user logs in using ssh: both user will be able to read/write files from each other

First I add each user to the other's group

sudo usermod -a -G other_group the_user

Then I add the proper permission (switching to the shared folder first)

sudo chmod -R u+rw,g+rw,o+r .

et voilà

It turns out that the executable bit was set for all files. I decided to remove id

sudo find . -type f -exec chmod -x {} \;