"Weak demons"??

Regarding the use of summoning demons during a long game when there are hundreds of creatures in the army in the final stages, it might not be very effective. After all, many useful skills will be unavailable with such a build... Well, okay, there's attack and fast portal opening, but it seems to me that luck/leadership with defense also wouldn't hurt to upgrade properly... I just think this way: summoning reinforcements from the abyss happens immediately (that's good), but after that, the summoned creatures won't last long, and we won't be dealing with an empty enemy army. Offensive spells also won't help much (it's better to learn tactics and mass acceleration). And with only one attack and not always suitable darkness, the demon won't be able to stand its ground, as it seems to me.