I hear this all the time. "Wing Chun is based on concepts!" I do think Wing Chun is based on concepts. But I don't think it is an entirely "conceptually based" martial art. I think Wing Chun is both technique based and concept based. You cannot negate the techniques themselves that define Wing Chun. There are concepts that are the intellectual constructs behind the physical techniques that guide how they are used and how they can be adapted to various circumstances. Then there are the concepts behind the strategies and tactics of the system. Both types of concepts are important, but when I have heard people talk about Wing Chun being "concept based" they typically want to discount the technique side.
I think the martial art that comes closest to really being "concept-based" is JKD Concepts! Most guys doing this system use the concepts to guide what they do and the techniques used are secondary. So sometimes they look like they are doing kickboxing, sometimes FMA, and sometimes Wing Chun. But Wing Chun itself is not like that. The techniques we use and how they are applied are as important as the tactics and strategies that guide them. So there is a level of "application-based" thinking involved as well as a level of "concept-based" thinking involved. Concepts guide the applications of Wing Chun specific techniques. Otherwise it stops being Wing Chun and becomes something else!
Which leads to another point. Wing Chun should be recognizable as Wing Chun! The concepts of the system are very important, but they guide the use of specific techniques that define Wing Chun. If you aren't using those recognizable techniques, then how can you call it Wing Chun? Maybe call it "Wing Chun Concepts" instead?? So IMHO, when someone puts on sparring gear and steps into the ring but end up doing kickboxing and nothing that resembles Wing Chun technique....I don't care how many "Wing Chun concepts" they managed to express....I wouldn't consider it to be Wing Chun if no recognizable Wing Chun techniques were being used. Maybe call it "Wing Chun Kickboxing" instead?? This would follow the JKD model. One group that is very open-ended in what techniques they use call it "JKD Concepts". There is a phase of JKD training when they are kickboxing with those concepts and they call it "JKD Kickboxing." Then there is another group that has something very specific in mind when they call what they are doing "Original" JKD or "Chinatown" JKD.
Anyway, just some things I've been thinking about lately!