Death wizards raise undead depending on their casting skill and number of Death books after battle, and units with Life Steal or Create Undead raise them based on their own unit cost. However Stone Giant sounds way too early for either.
The wizard can raise (books*skill)/5 value units, while units raise equal to their cost. Not sure about the value of the giant but it was something in the range of 300-600... so I have no idea where it came from unless the wizard has a high value unit with life steal. Like a Necromancer champion, or a vampiric sword, or the Wraiths spell.
The stack beating a demon lord or a great wyrm without causalities sound reasonable - the way math works, larger armies have an advantage in strategic combat. If those monsters were alone (or only supported by very weak creatures like sprites), the stack mentioned could have beaten them, especially as the wizard supported them by spell power and neutrals have none of that.
The wizard can raise (books*skill)/5 value units, while units raise equal to their cost. Not sure about the value of the giant but it was something in the range of 300-600... so I have no idea where it came from unless the wizard has a high value unit with life steal. Like a Necromancer champion, or a vampiric sword, or the Wraiths spell.
The stack beating a demon lord or a great wyrm without causalities sound reasonable - the way math works, larger armies have an advantage in strategic combat. If those monsters were alone (or only supported by very weak creatures like sprites), the stack mentioned could have beaten them, especially as the wizard supported them by spell power and neutrals have none of that.