The battle could actually be very simple for the living.
2 dragons protect the army from the other Dragon and bring it down or at least drive it away.
The white long haired guys and Giants are then targeted with scorpion artillery using Dragon glass tipped long range projectiles. They should be pretty easy to hit within a couple of hundred metres, particularly the Giants. The unsullied protect the artillery, again using Dragon glass Spears and daggers.
Simultaneously multiple dothraki Calvary teams complemented by westerosi Knights carrying Dragon glass tipped Lances drill through the zombie horde and charge the lieutenants and Giants. Each white killed takes out chunks of the dead army. It will be devastated pretty quickly save for the portion turned by the king. Admittedly we don’t know what that portion is.
Ignoring the king, if the Dragon is contained and you don’t lose your Dragons by throwing them away by recklessly engaging multiple giant archers or Walker spear thowers you should quickly destroy most of the dead army with the king forced to retreat or be killed or captured using the same tactics for execution later by the children left in the God’s eye.
Unless the dead have something big up their sleeve we haven’t seen yet i don’t think a direct confrontation with a large well organised and properly armed living army would go well for them.
unless of course Daenny and Jon go full Essington on us all. Both have display such quality on multiple occasions