I’m not a huge fan of fondant so I haven’t personally tried using a ganache drip on fondant. But, I’ve heard mixed reviews as to if it will work properly. Some people say it works just fine, others say the fondant bleeds and get weepy.   Please let me know if you do try it and it works!  Also, with some practice and a few tools you can frost a cake like a professional to look just like fondant.