I am not sure how you would functionally apply a martial art that avoids resistance.
By "finding" resistance, giving way to it, then redirecting it, or in some cases, emphasizing/enhancing it beyond where the opponent "thought" they would be.
You've done some judo, Drop? Or, something with an armbrag so you can get behind the person and strike from there or take their back is grappling is the better option?
For judo, just think advanced foot sweep - deashi barai on an opponent just standing still, or for the arm drag, think puncher/striker/boxer in some traditional stance about to pounce/swing.
If you try to sweep the foot out from under an opponent who is not moving, you hit a tree stump with most people of about 75% of your own weight and up (advantage to bigger types for this example) It IS ... possible... to kick the leg out, sure. But, it is really hard to do, and it hurts your foot and nobody wants that. Well, except Jack Reacher and it's why he's always wearing general-issue combat boots, but that's another story.
The giving way is to be mindful of the movement, and when the opponent moves his own front (advanced) foot, in any direction, the ... skill... is to continue such move beyond where the person wanted it to be, halt it a bit short o where they wanted it to be, or redirect it in a direction they did not expect it to go. Any success at all with this will start to break down their posture, causing reactions to get it back under control, which will, in turn, exacerbate the structural problems, and they end up falling. Or, you can really catch the technique right and they look like they just slipped on the cartoon banana peel (though I've never found bananas to be overly slick, myself. *shrug*)
Arm drag, same-same. If person is not throwing punches, but remaining hands-up at guard of some type, if/when you move in and attempt to arm drag, easy for them to defend by simple resistance, by movement or popping you with the other hand. But, wait for them to throw, let's say a straight right.
Step number one, get out of the way, duh. Then out of the way, you put your arm drag on While the person's punch is headed towards where your head was, and it's like you were magically teleported to their back and then you do whatever is next in line for you in this particular tactical situation.
The concept of giving way, blending, harmonizing and generally not combating strength with strength isn't unique to aikido as everyone here knows, or ought to know. It is central to aikido however, and with the possible exception of judo and the arts which led to the development of judo & aikido, like keto-ryu and daito-ryu, I don't think other systems put the blending at the top of the priority list in order to make their techniques work.
There's not much harmony in a good left cross. There is some... however, if your opponent strikes from his right side, and you slip and with he overextended you put the left cross on the button as the opponent goes by. Stylistically, I like to say cool stuff like, "Take that with ya..." as the opponent staggers away, but I think that's just me.
Sorry Drop, I got carried away. I should have just stopped with the first sentence with too many commas, but I've got my Starbucks shooting lighting through my fingers and that energy has got to go somewhere.