> whether the Anglo-Saxons displaced the natives or simply
> ruled them.
The problem is, in the literature, this is not treated as a question. It is a premise founded on the a priori assumtion that Anglo-Saxon is the mother-tounge of English. If one first concludes that that English is an Anglo-Saxon derivative then, ipso facto the previous people of Enlgand must have largely been replaced.
This produces what M. J. Harper alleges is the actual goal of "creation myth" making: drawing a fixed starting line for the birth of a nation. It is that unspoken psychological need to find a starting point that quickly finds a means of connecting the dots in such a way as to produce one -- no matter how circular the argument.