No worries..
Henge has at least 3 versions that I have seen, all of them not requiring anything out of the ordinary.
1st. Henge filled with glyphs (3-6 per stone) and sad glyph
This one is the most common.
2nd. Henge have 2-3 glyphs( per stone) and sad glyph
This seems to be at random, Less common.
3rd. Henge have no glyphs and no sad glyph
Caused by "bumping" and or Co-op play.
I have spent a lot of time at the henge and have seen the results first hand. Good looking out John, let us know if you notice anything else.