NR & Manjaro

Can I run Natrunner 2018.8 on the same machine with Manjaro 17.1.11? I know that both do not like to be in another Grub2 but their own. :huh:

Netrunner Rolling 2018.08 is built on top of the Manjaro base system.
Why would you have any issues running them on the same system?

There is no Netrunner 21018.8 release based on Debian atm.
However, if there was you would need to let Manjaro handle the boot loader.
This is due to the way in which Manjaro/Arch manages the Intel microcode:

It worked, I just did not install Grub for Manjaro and NR 's Grub worked fine. Thanks anyway.

Yes, other than the grub theme used, Netrunner Rolling (NRR), and Manjaro, both use the same base grub configuration.