Manjaro GNOME default look is quite OK, however it think it could be made a lot easier for new users.
A very popular feature of other distros like Zorin OS is the Layout Manager. I think it's very useful especially for new users coming from different setups like Windows/MacOSX/Unity or whatever.
I'm thinking that this would work very well with new features like manjaro-hello. Maybe @huluti could give his opinion toom since he develops manjaro-hello. For example, there could be a Tab for layout if the DE detected is GNOME.
I've already filed a feature request on Bugzilla: https://bugzilla.gnome.org/show_bug.cgi?id=781222 Feel free to contribute.
Here is the Zorin OS PPA. I've tried to port to Arch with debtap unsuccessfully but maybe there is a better way, or probably there is a way to do it from scratch. I am currently trying to write a GNOME extension but having a hard time.
Feel free to give feedback.
Edit: I'm writing a script that will showcase how this could work. Download it here: https://github.com/bill-mavromatis/gnome-layout-manager/blob/master/layoutmanager.sh
then chmod +x and run it with ./layoutmanager.sh --unity
Let me know what you think!