Yeah, I always looked to Wycliffe and Hus when I was a Protestant, trying to say that the Protestant Reformation was simply recovering the “true gospel” rather than creating a new or changed Gospel. The problem is that Wycliffe and Hus were still 1,300 years late, were mostly fighting over power, and both still had mostly Catholic beliefs.
I read the Church Fathers, expecting to see two strands of Christianity from the beginning-- the “true” “faith alone” “bible alone” strand and the false “works righteousness” “man-made tradition” strand. The problem was that the first strand simply didn’t exist in the Church Fathers, while a full reading of the Church Fathers showed they were extremely Catholic. Catholic theology was all there in the Early Church: Apostolic succession, the Apostles written words (scripture) and oral teaching (tradition) being authoritative, the Church having the authority to interpret the Apostolic teaching rather than the individual, the primacy of the Bishop of Rome, the true presence of Christ in the Eucharist, Mary’s perpetual virginity, etc etc was all in the first two centuries; yet we have no trace of a Protestant strand fighting against these Catholic ideas until many many centuries later.
To get back to the original post about why Protestantism flourished in Northern Europe; as has been stated earlier, there are so many variables that it’s probably impossible to pin down one.
I do think your point about Kings making the decision for the country to be very true. It’s not like today, where we read different ideas and make decisions for ourselves. Back then the monarchy would decide for everyone what the people were to believe. Many Kings converted to Protestantism out of political convenience, such as King Henry VIII. Heaven knows the monarchies were trying to fight against the Pope for political power well before the Protestant Revolt; the Protestant Revolt provided a new way for the monarchies to fight against the Pope together. Yet, we still stand, while all their monarchies are gone.