A smal bug!
 

I was batteling 22 Deathknights so i cast "doom" on him, and cast "berserk" on my swordsmen expecting huge dmg. , so my swordsmen attak him with there special attak and no critical dmg. , everione elce was getting criticals , i toght that berserk was the case so next turn i manuly attked with another stak of swordsmen ,again with the special attak, no critikal dmg.
The ability "smashing attak" does not get a chance for critical ?!?!?!

That isn't a bug, that's the way the game works.

When the swordsman uses it's ability it can't get a critical just like you wrote.