Clement & Polycarp?
Of course they are. Are you sure that you’ve read them???
If Clement and Polycarp were "protestants" then SS John and Peter must have been "protestant" as well, since they taught Polycarp and Clement!
But given that St. peter and St. Paul did not see eye to eye for a while, and since Protestants seem to favor St. Paul (like Marcion did), I doubt St. Peter was very "protestant."
But, maybe you can tell us specifically which part makes Polycarp and Clemnent "protestant," and at which point in the 1500 year span between Pentecost and Luther did the Church "stop" being "protestant."
LOL!!!