Actually, if you read the statements of the Culdee Presbyters carefully, you'll note that they are actually closer to Martin Luther's "strong" Predestinarian doctrine of total depravity, which holds that the Fall totally enslaved the human Free Will to sin.
Likewise the Waldensian Independents and AnaBaptists:
John Calvin's more nuanced "moderate" Predestinarian doctrine of total depravity, which affirms the Freedom of the Will while also affirming that All Natural Wants are depraved (thus man is free, but only wants to sin, and so sins freely), is essentially unknown to these pre-Reformation Christians.
Their doctrine of Total Depravity is the more simple doctrine of Luther: the Fall destroyed human Free Will, and now humans possess only a Sin-Enslaved Will.
For myself, I hold to the Calvinist view; but it is not exactly correct to call these Christians "Calvinists before Calvin". Their doctrines of Predestination ran more closely parallel to Luther's strong view of Predestination, than to Calvin's slightly more moderate view.