Resize display resolution of a macOS Mojave guest running in VMware Fusion 11.1
Reinstall VMware Tools

As was often the case with the competitor Parallels you mentioned, when the screen resolution fails to adjust you may need to re-install their software that embeds within the guest OS to enhance integration with the host OS.



From the main VMware Fusion app menu bar, choose Virtual Machine > Reinstall VMware Tools. 



This mounts an installer app within the Finder of your guest OS.



Run Install VMware Tools.app. After it completes, your guest macOS restarts. Then you should be able to redefine your virtual display resolution. Simply grab the corner of the VM window on the host Mac, and grow/shrink the VM window. The size within the guest macOS auto-resizes. 

You cannot use the System Preferences > Display within the VM to re-size. Instead, use this stretch-the-VM-window maneuver.