Sub-Roman Britain (Cavalry etc)

[marka]

with the norm probably sliding toward the hungry pole for several centuries.

Why? I doubt very much that the people working the land, living outside of big towns, noticed much of a difference. Sure, the man that they had to give stuff to dressed differently and spoke differently. Not that they ever spoke to the man in charge anyway.

true they probably wouldn't
if the 'saxons' and 'angles' had any sense the kept as much as possible the same and the 'british'lords in newly conquered saxon lands probably retained their positions.the british lords simply forwarding part of their tribute to their new overlords.they could also have used 'british' overseers as well.