For the record (historical record) the english were less civilized than the vikings, just in case you wanna use a semireel scenario.
Their military systems were inferior, tactics were inferior, weapons were inferior etc etc.
the latter english military system was introduced by the vikings. And later refined by the normans (ex vikings mixed with french). Trading cities were also founded in most of the british isles and helped the english to escape the so called dark ages. (note scandinavians never called it dark ages because for them it was a time of expansion, riches etc).
All the impressive castles of england was build post viking and norman invasions by the normans. The anglo saxons primarily used wood to construct fortifications etc, while the normans used solid stone and more advanced techniques introduced from europe.
I think it would be cool if you used a viking theme or covered the time when the danish viking king Knut (canute) ruled england with his elite soldiers, the huskarls.
That would be original and interesting.
Anyways I will keep and eye on this one.