Okay, okay... I shall ignore my assertion that there Jutes, Saxons, and Angles (last I checked Denmark is part of Scandinavia)- in early part, they did raid and loot the British Iles bringing their wealth home
Not really in the Vth century. By then we have relatively not-hierarchic communities settling in, with new local chiefdoms arising from North Sea exchanges, mostly trough Gaul. North Sea raiding from Old Saxony is more noticable in the IIIrd century.
As for Danes, while raiding is not to be written off in the Vth, there's no much archeological or historical account for this, while we do have some for the continent.
It doesn't mean that Germanic settlement in eastern Britain was especially peaceful, but it was not destructive as Viking raids were (for the good reason, arguably, that Gaels and Picts already helped themselves).
On seeing that Iron Age Britain was weak and pragmatically leaderless that like Rollo centuries later decided to move right in and set up petty kingdoms.
That is simply not supported archeologically or historically : Germanic kingdoms became to appear in the VIth century out of a simple/complex chiefdom process that probably mixed up native and Germanic populations (especially for Wessex), the first tribal petty-kingdoms largely espousing the shape of sub-Roman Britain entities.
There was no planned conquest of, say, Angles in no small part because the communities settling in the Vth century weren't unified at all, were mixed up and only tought themselves as Angles in the middle of a long process of structuration.
At the contrary, Rollo's dominance (or virtually any Viking polity in Northern Europe) is not the result of a political structuration out of desintegrated region, but a opportunistic presence (on which familial communities are hard to spot : we're rather talking of warband outposts) and takeover of maritime/fluvial access, which get stabilized with a formal modus vivendi with native polities and actually depended from it giving that most of these establishment were eventually reappeled : Rollo's Normandy is more or less the exception, thanks to a late settlement of Anglo-Danes and Hiberno-Norses in the early Xth century.
I'd suggest, if you're interested,
Britain after Rome by Robin Fierning, and Le
Monde Franc et les Vikings by Pierre Bauduin.