No one is denying that atrocities were committed by evil and irreligious men on both sides of the various reformation wars. The horrors visited upon the Waldensians were an everyday event in the campaigns of Cromwell against the Scottish and Irish Catholics and were similar to the those committed by the Protestant Armies of Sweden across Bavaria. The conduct of either side justified the reciprocity by the other then or now.
Was Oliver Cromwell’s army fielded literally by the church? No. Were the papal armies? Yes.
It’s a distinction with a difference. Cromwell’s excesses were fuelled in part by widespread outrage over treatment of the Waldenses, he returned the atrocities in kind. Is this right, is it Christian? No, but words mean things and actions have consequences.