Should Mummies be Susceptible to Stun?

I noticed when going head to head mummies that mine were stunned. This does not seem right that any mummy can be stunned by another. Surely mummies are immune to their own power?

I have come across mummys but due to using scream and having a big army I haven’t noticed. Would be rather stupid if they can be stunned though

They can be stunned, both by other mummies & boosted ogres.