PS And you still haven't bothered to respond to the examples from my message about the "aggressive stance."
Why can't you dig up a dead support hero? Because the very idea of digging up dead heroes is an abuse of the Heroes' mechanics. On regular maps, it's not a big deal, but on a mirror map, it's a serious imbalance that shouldn't exist.
Some time ago, this issue was raised on the Heroes forum, and there was a suggestion to either level down or reset the stats of upgraded heroes (as in Warlords) or move them to the end of the queue when purchasing. Perhaps this will be implemented someday.