To be kind to your your enemy is to be cruel to yourself.
Your opponent attacks you, you push him away. Your opponent attacks you again, you push him away again. How many times do you have to repeat that process?
I always like to ask Taiji guys what will they do if they have to use Taiji skill to kill. They all look at me as if I came from another planet. When you have to fight against multiple opponents, The sooner that you can "finish" with one opponent, the better chance that you can "finish" the others.
If you can drop your opponent with one punch, everything else are not important. So How can you drop your opponent ASAP? Your opponent attacks you, you borrow his force, add your force on top of it, and finish him with A + B > B.