[H3SW v0.8.1] Possible bug system combat

I'm not sure if this is a bug in combat system.
So less damage attack of a monster, for example, i have a nr. 200 archmage with my heroes with 60 attack point, and they do not kill in first time a nr 45 power liches of a enemy with seven defens points...
Or another big example.
100 of my titans (heroes 27 attack point) do not kill in firs time nr 80 lord vampire.
Dragons the same.
It seems that titans and black dragon are not so powerful like in homm2 vanilla...