I've trained in both Muay Thai and Wing Chun before, both several years, I would say the mix would be amazing since MT can deal with long-mid range and WC and deal with mid-close range. Since I've sparred with many different kinds of martial artists (boxers, MT boxers, WC, Capoeira, Tai Chi/QI/Ji etc., you name it), I've noticed that WC is actually quite situational. Let me elaborate. While being clinched by your opponent (which should be quite difficult since you know WC puts up the hands in front and deliver hits as your opponent is closing distance, a simple chain punch would do), using Chum Kiu while delivering an elbow diagnally from hip to chin to the direction while u are turning may break the clinch partially, and you may use the other hand to swoop in and give your opponent a side palm strike or a slice in the neck. With this split-second (it's actually around 0.5 seconds) of shock when the opponent is hit, you may break the opponent's balance while giving a step/kick to the knee/shin. As he/she breaks down, it is a great opportunity to grab the hand/arm and give him/her another barrage of kicks to the legs and punches or palm or whatever you feel like, as long as you are staying in good balance and in form. There are so much more to share, but I guess I'll pause for now.