I don't know if you guys are thinking the same, but for me, the Engineers at Covenant seemed like an amalgamation between the prisoners from Fiorina "Fury" 161 and the monks at "Vincent Ward's wooden planet".
Seriously think about it, they seem more like a bunch of crazy guys living in some kind of dystopian post apocalyptic society, instead of these majestic god-like beings that we saw in Prometheus.
I know that there is a more dull explanation for that, but, what if they just decided to recycle these old ideas and concepts in order to use them in Covenant?