The idea of the more civilized English war depends on one word: English. The moment Scottish or Irish forces got involved in ECW the English needed no German to learn how to be extremely brutal. And raping, plundering and all the other pastimes of 17th century soldiers are not only done by Rupert's men.
And in a bigger British area? Let's not talk about Scottish clan feuds. Or the centuries of war in Ireland.
Units like Wentworth's horse that "only their fiends feared" are no rarity in ECW. There was a reason for clubmen defending the counties against both sides.
Basing house storming, the prisoner Inigo Jones was plundered of everything, even his cloth and went away in a blanket. Feeling glad not to be among those killed in cold blood.
Individual accounts from that time in England are a lot like Grimmelshausen Simplicius TYW stories. There was no Magdeburg but enough awfull things.

