As for whether to perform exceptionally and take Chenliu directly, or to perform normally and consume more than half of Chenliu's troops, both are extremely favorable.
The first option needs no explanation. If the battle ends directly, the strategic objective will be achieved immediately. However, in Liu Ye's view, this possibility is extremely slim. After all, anyone that Cao Cao values to guard Chenliu cannot be an ordinary general.
The second option is most likely. Consuming half of the troops is also a massive blow to Chenliu. Even if the remaining forces retreat to Chenliu, they will be overwhelmed remnants, which is a major setback for Chenliu's situation.
By then, whether it's morale decline or a lack of troops, after a few days of besiegement and strong attack by Liu Ye's forces, internal turmoil will erupt in the city. At that moment, capturing Chenliu City for Liu Ye will be just a matter of a flip of the hand.
