Jude, you are yet again entirely correct when you say that "Calvinists do ourselves a misservice when we overstate our objections to Arminian theology". We often do ourselves a mis-service, just as you state.
But, with all due respect, look at John Chapter 8.
Pelagianism is the belief that Man is able to respond to God even without Prevenient Grace.
But as John 8:30 makes clear, these False Disciples had received Prevenient Grace. They were Convicted. They even claimed to follow Jesus.
One thing only was lacking -- they claimed that the Unregenerate Man was not absolutely and utterly Enslaved to Sin.
And for this Error -- this fundamental, Satanic error -- Jesus Christ employed His harshest language EVER.
NOT PELAGIANS. These people were Convicted. They had received Prevenient Grace.
Let me repeat that: They had received Prevenient Grace. And yet -- Jesus called them Liars, Murderers, Children of Satan.
They had received Prevenient Grace. This is the bonafide Truth of John 8:30.
Jesus was condeming Arminians.