The difference is one group uses mental coercion and mental torture. The other group does both, mental coercion and torture and physical coercion and torture, even death. But the essence is the same, both groups take away freedom by coercive means. So the comparison is adequate if the differences are noted too.
The great Christopher Hitchens (rip) compared Christianity to North Korea several times. Intelligent people understood that Hitchens was not equaling North Korea and Christianity, but that both groups use similar systems; tyranny to control the masses. I agree with Hitchens comparison.