Actually, the arminianism we know is the product of arminius’ followers after his death, the remonstrants. Personally, I don’t think he would have gone where they went. Every time he went before a tribunal he came out in the clear. They didn’t defrock him. Those later followers were repudiated.
DrE, if she were still here, would probably argue with me the fine points of this, but the fact remains that Arminus never wanted to leave and his opponents were never able to get him kicked out.
I think he was Heidelberg instead of Westminster, but I’ve never been able to tell the difference.
IIRC the Heidelburg Confession asserted the total Soverignty of God in the selection of the elect, but unlike the Westminster Confession, the Heidelburg Confession did not categorically deny that the methodology used by God included some aspect of foreknowledge.
It might be a different confession I am thinking about, but it’s late and I’m lazy.