I stumbled across this video about the Nordic Bronze Age which sums up where many of my ideas for Bronze Age Orlanthi come from, although I would take a fair number of the "Indogermanic" and God Learner hypothesis with big grains of doubt.
A number of interesting facts remain, like access to the Pannonian bronze through trade independent from the sea trade in the Mediterranean, cultural exchange through the amber trade, etc.
I'll look out for more info on the Pannonian Bronze Age, which would be even more pertinent, but when looking at things like the presumed battle of the Tollense Crossing and migration evidence as with the Egtvedt Girl (mentioned in the video), that battle makes a lot more sense.
As for missing structures: with quarriable stone being absent, the archaeological record relies mainly on holes in the ground. The part of Germany where I live has virtually no bedrock (there are two exceptions, one former mountain of gypsum, formerly crowned by a stone castle, that was quarried down to half its size, and a high reaching chalk area near Itzehoe which is now quarried for cement), but there used to be 100 families of landed knights (who had special liberties in the original counties, then duchies), each of them with at least one fortified homebase. None of those castles survives, in a few places some holes in the ground did survive the intensive plowing. Any grandiose structures from the Bronze Age would have suffered the same fate.
That's why I have my difficulties with the descendants of Durev the carved man being so avid masons. Dwarves make up for a lot, but honestly, Clearwine in Cypriotic or Thessalian architecture does feel as wrong as would Roman opus cementitia. Fortunately, most other Orlanthi appear to be carpenters rather than masons. Giving the 3rd century Berennethtelli something like Peter Jackson's Rohirrim splendor wouldn't be wrong for my Glorantha, and would make the "steadburning" that claimed Brolarulf only that way more impressive.
Edit: Silly me. Here's the link: