That's a lot of different flavors going on there. Try just a simple salt and pepper brisket, pretty good stuff, let's the beef shine. I've tried many different liquids in the foil when I wrap my briskets, but for the past year or so, I've settled in using one of the following: 1 cup of beef broth, or 1 cup of reserve au jus from a previous brisket cook, or 1 cup of beef broth made from a paste called Better than Bouillion. The best of the 3 is the reserve au jus. I do this for my comp cooks as well as just cooking for friends and family.
As far as the meat being dry, that really could come from not cooking the meat long enough. I use the IT just a guide for checking tenderness. I'll start checking the tenderness with a toothpick at 200 IT, then again at 205, and again at 210 until the toothpick slides in the meat (in the flat section) easily, like into butter. Once this is reached, I'll pull the brisket, and rest in cooler with towels wrapped around it for at least 2 hours, but usually at least 3 1/2 to 4 hours for comp cooking. The slower the IT can drop on the meat, the better the fibers will relax and redistribute the juices from the meats surface towards the center. Ideally you don't want to slice into the meat until the IT falls back below 170.