The earliest evidence for runes is the Meldorf brooch, dated around 50 AD. So no runes for the Cimbri.
Petroglyph production declined sharply after 600 BC and it is really difficult to date a petroglyph. Furthermore, there is not a large quantity of petroglyphs in Denmark. Those were mostly found in Sweden and Norway.
I would avoid petroglyphs for the Cimbri.
It looks a lot like a boat burial, when a person is buried with a boat. Which is not attested for this period.
The sinking of the Hjortspring boat is more probably a votive deposit, an offering to deities, from a war booty or a trophy.
Furthermore, you choose a very small boat and you emphasize much more on the stone circle. Which is a bit problematic because the boat is probably the most important part.