Hello,
Completely agree with you.
You forgot the best of this :
Ennemy goes back from his spawn point. So the ennemy is back from his spawn points.
So you advance. So you are on, or past the spawn point.
*And his knights spawn in the middle of your archers *
Useless to make a drawing to explain you the result lol
This can almost result in a defeat : dumb player archers hitting only closest targets, they stop arrowing what they were supposed to kill and get killed by the reinforcements... anyway that resulted on irrevelant losses...
I think the spawn points should be dynamic instead of static, so if the ennemy goes back instead of forward, his reinforcements come close to his actual line of defense. And maybe adjusting the spawn point for the player or AI who has advanced a lot on the map.