It's been interesting to learn about the reasoning (or post-facto explanations) of that seemingly anomalous major 3rd gap. I can see its advantages, like it enables certain barre chords.
Apparently, the tuning invented by Robert Fripp is called "New standard tuning", based on all fifths. I like the audacity to call it a new standard. :)
> C2-G2-D3-A3-E4-G4 (from lowest to highest)
> the five lowest open strings are each tuned to an interval of a perfect fifth
> the two highest strings are a minor third apart