In kenpo, taekwondo, kajukenbo, krav maga, and any style there is a concept called a marriage with gravity or back-up mass. This is about using your whole body to add power to a strike, whether this is a forward facing strike or more of a downward motion. If I just punch with my arm and leave my body behind, then I lose out on the mass of my body. Since force is mass times acceleration, this drastically reduces the force of my strike. This even ignores the fact that I can off-balance myself by not keeping my center of gravity between my legs but instead reaching too much with my fist.
Even that concept of the center of gravity or dan tian translates between all styles of martial arts. This is why if I bend at the hips for a single or double leg takedown I am asking to have my face planted into the ground instead of putting my opponent on his or her back. My center of mass has moved in front of my feet then. By shooting in (a wrestling term) I have much more control and can safely go corps-a-corps (body to body) with my opponent.
Stances also have distinct purposes between them, which changes whether I have my feet wide, planted, heels off the ground, weight distribution and many other details. If I want stability, I would not choose a cat stance, where the majority of the weight is on one foot and the other foot is lightly resting on the toes. However, that stance is great defensively. I have three limbs ready to strike at any time.
Similarly, the specificity of a weapon also frequently has matches between styles (even if I think there is more detail and variety in kung fu). No matter what style I studied, it is always the middle knuckle that is used. Sometimes the bottom three knuckles are used for an intercepting fist, and sometimes the top two knuckles are used with strikes like a square punch. There is always a distinct difference between a slap and a palm strike. In my experience, kung fu goes more in depth with eye jabs, ear pulls, and throat strikes.
It is interesting when the phrases change. My training was focused on center line and getting off it, and a co-teacher of mine is more focused on off-angling. But both concepts are the same. Getting toward one side of an opponent allows more of my limbs to strike (if I stay facing them), while my opponent is restricted to that single side. A step vs a slide in that rotation and movement can be a change, and I find that the step would reduce friction and give a small amount more speed.
I believe that this focus on principles allows for a growing martial artist to apply them more broadly than a specific memorized pattern teaches. This way rotation and backup mass can be applied to a kick, a punch, a throw, and an elbow, as opposed to rotating from a horse stance to a forward bow with a cross in a kata. Knowing the purposes of stances being for defense, evasion, aggression, or stability allows more fluid adjustments to be made between them depending on the situation that one is faced. It is from these principles that an effective personal style can be developed by mixing various techniques from effective martial arts practices.