Yet on this subject I have Gomarus himself consenting with me; for, soon after Trelcatius had published his common places, a disputation on the Trinity having been proposed in the University, Gomarus did in three several parts of his theses express himself in such terms as were diametrically opposed to those of Trelcatius. The very obvious difference in opinion between those two Professors I pointed out to the Amsterdam minister, who acknowledged its existence.
Of course, these translations are in "all difficulty olde English style" and that difficulty could be used by some on FR to suggest something is being said that isn't.
In this passage, Arminius says simply that the Father is not the Son is not the Holy Spirit is not the Father. It's a classic trinitarian formula.
He specifically here rejects tri-theism and Sabellianism. "To these remarks I subjoined, "that from such an opinion as this, necessarily followed the two mutually conflicting errors, Tri-theism and Sabellianism..."
Would they prefer he accept these two???
For Arminius to say Gomarus agreed with him is too easy. He doesn’t show us where they agree. He just states it. A lot like saying Calvin didn’t believe in limited atonement. Easy for people to say, but clearly an absurd, untrue comment, disproven by reading Calvin’s own words.