That sounds plausable but a study done a few years ago established that there are a high proportion of male Norse ancestors in the Danelaw.
Don't forget, unlike the Saxons the Vikings were actually driven out within a few generations, it's unlikely the genetics had as much chance to "travel down" the social strata, hence less Norse blood.
In answer to the question about who Britons are, most a decended from pre-Celtic stock.
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