Do you think Vikings were as big and strong as lore would lead you to believe? And how did they get that way politically speaking?

I can't say all, but I have done some reading on the Vikings. The big issue to me is this.

They aren't warriors. They are more like pirates. Vikings attack small, weak villages for profit. (Goods). They were not attacking formal armies.

How tuff is it to beat on some farmers, and priests?

I would say they were very strong seafaring men, but would not be able to fight off a formal army/navy. Very interesting question btw. Thanks for posting it.

Studies have shown that the Vikings on average were shorter than the Scandinavians today, but, again, on average taller than the Anglo-Saxons. There are also texts from that time from Britain and the Middle-East that describe the Vikings/Normans as tall.

As for their fearsome reputation as giant warriors, it's probably also worth considering that scrawny Thorvald might decide to stay home and tend the farm, while his stronger brothers and sisters went raiding or worked as bodyguards abroad.

Nah they weren't like the media portrays them. They were mostly just farmers, and they never had horned helmets.

Vikings were shorter than modern man