So, what exactly does 'define' a complete Martial Art? Surely you are not suggesting an 'empty hand' art is complete?? Karate is not complete.
Are you actually being serious???
These 'sports' you list are just that. Sport. Martial Sport, if you prefer. All 'designed' or updated in the last century to enable a safe 'competing' platform. Don't confuse them with Martial Arts!!!
I will offer my definition of 'complete' and see if anyone else can add to my idea. I believe a complete Martial Art must have representation of various areas of practise that help develop us as human beings, not just to fight for fighting sake, but to defend ourselves, our loved ones and the weaker/less healthy members of society. We do this by training people in a number of ways:
1. Form practise. Solo training to enhance technical understanding and basic foundation movements key to a systems development. Many forms have had individual input, becoming more of a 'stylistic' representation of said person/s. This isn't a bad thing, as long as the system knowledge is not sacrificed and lost.
2. Interactive practise. Call it sparring if you prefer! But when you train with a partner to develop your skill, this is 'interactive martial play'. It is our Chisau/Looksau/Gorsau and Sansau platform. But only if you remove the 'competitive' ego driven nature most younger students seem to have these days lol!
3. Equipment practise. Take our Wooden Man as an example, it is unique to our system because of it's scientific design but common in almost all other Chinese Martial Arts as an apparatus that assists in power development. Just like hitting a tree, wall bag, makiwara board or modern boxing pad. Equipment is key to actually feeling contact without injuries.
4. Weaponry practice. I know it's an old cliche and many may disagree, but without weaponry training you're not really training a 'Martial' Art. We are lucky in Wing Chun that we hold two key weapons that enhance our short and long range fighting skill. One of the only Chinese Systems that has detailed knowedge of both imho using only 2 base weapons rather than the original 18 Lohan designs.
5. Cultural practice. Whether it be BJJ, Boxing, Muay Thai or Judo every art has it's origins and history and just learning a little about theoriginal culture of any give Martial Art may help join a few dots together. Wing Chun is know to be able to 'talk the fight' due to our basic concepts and if two Sifus meet they have a language and culture they can share, before they even cross hands.
Now, put all that together in a short period of time. It isn't difficult to see how this forms a complete understanding of the Wing Chun system, and if you are honestly missing anything here, go find someone that can help you because this is as complete as any Martial Art need to be imho.
This is the very reason we still exist as a system. This is why I find it difficult to watch people 'add' things like Escrima, or BJJ to a Wing Chun curriculum. We are as complete as we can be, and most if not all the hard work has already been done by the ancestors. All we have to do is continue and Wing Chun will still be here in another thousand years