Another strategy:
1. Switch to Theocracy+warrior code, stay Agrarianism for extra pasture hammer and work rate.
2. Starting army go capture Viking workers and maybe a city (i.e. Malmo with only 1 archer), Settler and missionary follow the army.
3. Settler found Tallin or Riga or Helsinki. Gift the captured city to French to prevent Viking recapturing it, you can't defeat them yet. One galley stay near your Baltic city.
4. Homeland build pagan temple(chop them ASAP) - warrior - barracks, Southampton and Newcastle build stable.
5. Make peace with Vikings, 1 longbowman and captured worker and 2 galley back home. Have 2 units in Southampton boarded.
6. Find chance that French found Brest or build dye plantation, assault! Capture workers, conquered Viking city(like Malmo) and raze Brest.
7. Switch to slavery, mercenary and buy an army to conquer or capitulate France.
8. Buy galleys in Marseilles and go conquer Egypt.