Or maybe the game is less about luck than we think: One can try to let the opposite heroes fight with some rookies before they fight the heroes, so it might be more about skill...
one can try, but there is no guarantee that it will work. and as you showed, you can still force a wounded soldier to retreat by dismantling/upgrading the military building. you lose some building resources, but they are worth less than military ones.
don't get me wrong. i'm not saying the game is luck-based. if there are two strong players who have come out very close from early game, and they clash by the time they can field the first hero, and they both make the first hero at the same time while also having similar level of development, and they decide to fight there, and the two heroes fight each other... ok, then it becomes a matter of luck. but for luck to matter it requires that both players are that close for all the game.
luck was an important factor in two of our games because we both played so well and were so close that a single hero fight going one way or the other could change the game. in those matches where i did not manage to keep up with you early on - or in all those matches when one of the player comes out with a clearly better economy - luck is not a factor.