The most accurate response to the question about how the state-sponsored atrocities committed against the Cossacks were different from Soviet actions against other ethnic groups is:
While many Cossacks were killed, many others were eventually reintegrated into Soviet society using new ethnic identities.
This reflects the unique position of the Cossacks in Soviet policy, where the regime aimed to suppress their identity and assimilate them into a broader Soviet identity, differentiating their situation from other ethnic groups.