Concentration/number of weapon types in the pre-and immidiate migration period.

[Incongruous]

Well in Ireland it also meant the use of light cavalry, an important development.

I suppose what I am also asking is that if like the Vikings the Angles, Jutes and Saxons were weapon "heavy", would they also have influenced the number and type of weapon used in Britain.

In order to even begin talking about that I need to know whether the Northern Germans and early Scandanavian peoples eg. Jutes were in posession of more and better weapons and armour. In Northumbria it might be the case that the Germanic invaders were more heavily armed than others of the area and period.

As for the case of Longer swords, the use of the short sword or Seax by the Germanic invaders is noted and iconic. The Romans had of coarse switched to the Spatha, but I believe that has to do with their encounters against the Persians and such, a higher emphasis on cavalry than before.

The Axe was obviuosly a Viking infusion as it was all across the British Isles. Of coarse in Ireland such axes tended to be slimmer and of lesser contruction due to the lack of Iron. Of coarse the Irish assimilated and imitated the Vikings, I am not against the idea but for it.
But this is not what I wish to discuss.