To neutralize force, use the ball concept.
Consider a ball suspended in some water. When you push this ball it will rotate in some direction, thus neutralizing the force of your push. If you push the ball dead center, it will move in the direction of your push.
The ball concept uses the ideas of ROTATION and TRANSLATION. The turnstile concept just uses the idea of rotation.
When you push against a turnstile, it just rotates. It cannot move in another way. When you push on a ball, it can rotate or it can roll. Tai Chi practitioners use more of the ball concept. Wing Chun practitioners use the turnstile concept because they do not like to back up. Backward movements are a waste of time when your goal is to just move forward towards the target.
Split second mistakes will get you beat.
When you confuse ideas or use conflicting principles in your fighting, you will lose to people who are good. If you hesitate because you don't know whether to back up, or to advance, or to turn you will lose to an opponent who has no hesitation in what they do. If you train in the methods of art A on Monday, art B on Tuesday and art C on Wednesday, then in the real fight which art will you use. At the slow speed, you have the option to use any art. At a high speed any hesitation could end your life. Many Jeet Kune Do people feel that the more arts they mix together the better. Wing Chun people disagree with this concept. If you are really serious about self defense and combat, you have to make up your mind what you really want to train! If you are just having fun and playing around then it doesn't matter what you train.
If you practice just pushing, shoving and applying fast hard hits to your opponent, independent of what they are doing, then you are practicing in the hard external way. This way can be effective if your opponent is slower than you and weaker than you. The hard way leads to quick early results but in the long run it will be a detriment to your martial arts career. The internal method is more concerned with effective force neutralization using your sense of touch. This skill is very difficult to achieve and very difficult to deal with once it has been achieved. Stronger people find the external way of training easier and more satisfying. But for that you don't need Wing Chun.