The above are just concepts, you'd need to agree any form of reference to arm with them directly see my edit at the end of this post. Is there a particular reason you want the logos on there anyway? Surely a bootsplash would suffice handing over to a custom wallpaper using manjaro hues which doesn't have to feature the logos necessarily.
With regards creating new wallpapers, I'm fairly sure some of the existing catalog of manjaro wallpapers can be cropped to the right dimensions if the creators made them in high enough resolutions. Like this? Obviously ask the creator first if they can do it as these have lost a little quality being rejigged in GIMP.
EDIT - going back to the arm logo, manjaro at some point really need to fill out their permission form as they can stop you from using the arm name regardless of typeface.
Do not replace the logotype with a different typeface.
With that in mind, I'll resubmit my one above without the arm logo just in case they refuse permission and suggest nobody else adds the word ARM in any form either for now.