I'd be interested to hear more about that. I love a good bit of amataeur history and my (amateur) reading of that sort of thing is that the 'benevolent' - you can worship anything you like - or 'religious toleration' thing was practiced by some of the actual most oppressive and murderous regimes in history.
E.g. Genghis Khan's mongols - you can worship anyone you want - but you better acknowledge us as overlords or you're dead and so are your family and your pets, and the rest of the city - and we may rape your daughters in front of you too. Basically yes you were free to worship your own god - but otherwise a slave for them to abuse as they pleased.
Romans were not so far off - worship anyone you want as long as one of them is the emperor. That's why Jews and Christians fared so badly with them - the 'one true god' thing didn't include a self-proclaimed god-on-earth.
A lot of the very famous religious *intolerance* is also usually a reaction to bad factors elsewhere. Nations historically and peoples, tend to be quite relaxed when times are good. Give them a dose of invasion, massacre, plague, famine etc. and the one-true god lot - who are usually led to believe that they are the chosen ones who god favours - look inwardly at what they've done wrong to deserve this punishment. Why have we angered god? That's when those who don't worship god 'correctly' or those of other faiths get the short-end of the stick. It also massively increases the proportion of zealots. Perhaps we're not worshipping god hard enough, or enough...
Post-enlightenment period (US revolution, French Revolution type period-is up to now - we are still in this period) is when 'rationally' kicked in, the thought paradigm prior to that was that god was behind everything so bad things must be because of a punishment from God. So what might now be debated as to reason or cause of bad things - would back then have been seen very differently.