Which creatures from the alternative upgrade options do you choose?

Well, if the opponent isn't an idiot, they wouldn't place two units in the path of the cavalry, so their ability might not even be useful. And ignoring defense will definitely work 100%.
The new mage upgrades cause a lot of trouble for races with chaos magic. It's almost like cheating: gargoyles are immune to chaos, obsidian golems are resurrected, even irresistible magic is powerless against them, battle mages have resistance, viziers have resistance... Plus, some of them also protect adjacent units from magic. And no one seems to know – do battle mages attack their own units? The description says no, but the list of their abilities says yes...