The hero cannot participate in the battle, which is strange...
The leader of the army has always been at the forefront of the battle, but now this opportunity has been taken away, allowing him only to cast spells and shoot. And where is the hand-to-hand combat? Because of this, the hero cannot leave the battlefield alone. Allegedly, without an army, he is useless... he can't even retreat in time.

Added 3 minutes later
...and also
on the battlefield, it sometimes happens that you can't see where your troops are and where the enemy's are!
and it's annoying how much time you're given to think about an attack! How can you choose the right spell in 10 seconds?! But, to avoid this, they came up with a better auto-battle system; it conducts battles much better than I can while I'm still thinking about what to choose...