...the States of Holland under the influence of Oldenbarneveldt supported the [Remonstrants], and refused to sanction the summoning of a purely church synod (1613). They likewise (1614) forbade the preachers in the Province of Holland to treat of disputed subjects from their pulpits.Interesting. It appears that Oldenbarnevelt was, like Arminius before him, very much an Erastian in believing that civil authorities should have final jurisdiction in all matters (including those within the church)....
The States of Holland, also by a narrow majority, refused their assent to [a national church synod], and passed (August 4, 1617) a strong resolution (Scherpe Resolutie) by which all magistrates, officials and soldiers in the pay of the province were required to take an oath of obedience to the States of Holland on pain of dismissal, and were to be held accountable not to the ordinary tribunals, but to the States of Holland.
Of course, I'm sure you recognize that Oldenbarnevelt's arrest and execution was the result of the political battle being waged between the States-General and the States of Holland, and not the result of the theological battle being fought by the church synod (as the OP implies).
Interesting climate, wasn't it?
Definitely a climate from which good decisions and good directions for future generations would flow.
I'm sure, as well, that everyone was freely speaking out without fear of reprisal.
It would almost make an observer of that history reluctant to allow that era to be determinative about anything.