It's good to know the Arrow is Mac compatible but the installer isn't. You can only download an .exe from JF and you can't use an .exe on a Mac (at least not just like that). On a Mac you usually get a .dmg file for install, although in this case a simple zip with all files in it might also do the trick (for manual installation).
There is a Mac option for the download & a zip file is the result. The 2 aircraft folders should then be manually installed to:
/Users/yourusername/Library/Containers/com.aerofly.aerofly-fs-2-mac/Data/Library/Application Support/Aerofly FS 2/aircraft/
The aircraft appear in the selection menu but on start the aircraft defaults back to the c172.
Possibly a result of UNC/Posix double slash mismatch in the path? Possibly also upper/lowercase mismatch in the username?
16.05-tmsimulator: loading model pa28r201t...
16.05-tmmodelmanager: model: (name='pa28r201t') (directory='/Users/XXX/Library/Containers/com.aerofly.aerofly-fs-2-mac/Data/Library/Application Support/Aerofly FS 2/aircraft/pa28r201t//')
16.05-tmmodelmanager: loading configfile '/Users/XXX/Library/Containers/com.aerofly.aerofly-fs-2-mac/Data/Library/Application Support/Aerofly FS 2/aircraft/pa28r201t///pa28r201t.tmc'
16.05-tmmodelmanager: contact points 3: (1.983 0.000 -0.794 r=0.180) (-0.431 1.553 -0.789 r=0.160) (-0.431 -1.553 -0.789 r=0.160)
17.06-tmxgl: ERROR: (texture 'headset_senn_specular' not found)
17.08-tmxgl: ERROR: (remove invalid texture at index 'specular')
17.08-tmmodelmanager: loading dynamics begin '/Users/XXX/Library/Containers/com.aerofly.aerofly-fs-2-mac/Data/Library/Application Support/Aerofly FS 2/aircraft/pa28r201t///pa28r201t.tmd'...
17.09-tmfile_properties: WARNING: property 'InputPosition' is not a member of type 'flight_management_system' hash=18297074990155055016.
17.09-tmfile_properties: WARNING: property 'InputVelocity' is not a member of type 'flight_management_system' hash=11758052505459015428.
17.09-tmfile_properties: WARNING: property 'InputGroundSpeed' is not a member of type 'flight_management_system' hash=16557520335897305405.
17.09-tmfile_properties: WARNING: property 'InputVerticalVelocity' is not a member of type 'flight_management_system' hash=1564061341192855582.