Penn, seems like Old School has you headed in the right direction. For true Texas brisket, from the hill country region that is, the wood of choice would be Oak, Post Oak mainly, but as you get into different parts of Texas, we may tend to run Hickory or even Pecan. South Texas will traditionally run Mesquite. Have to remember, Texas is a rather large state, our regions are bigger than most states! LOL. If you are working on brisket techniques to be able to compete, especially in the upper Northeast of the US, cooking in KCBS contests, you might want to take a KCBS CBJ class, then judge a few competitions to get to know what flavors are being used up there. I would seriously doubt that a true Texas style brisket is winning. Heck, true Texas style typically won't win in Texas either! Most comp briskets are bordering on roast beef flavor, from both the injections and grade of beef being used. As far as injections, there are several popular ones being used on the circuit (Butchers BBQ, Kosmos Q, Sweet Smoke Q, Fab B) and rubs, can't count the number of different rubs being used (Big Poppa, Oakridge, Butchers BBQ, Simply Marvelous, and countless others). Woods will vary from region to region as well.
I don't think the injection had anything to do with dryness, this is typically from lack of internal marbling with the meat itself. If you are planning on competing, you'd better step up your meat grade first, practice cook until you can't mess it up, but I would for sure look into judging first. Good luck and feel free to shoot me any questions you might have. A few resources that might help you with your desire to compete...
Buy the book "Starting the Fire" by George Hensler. Good guide and look inside comp cooking.
"American Smoke" video documentary about comp BBQ (especially in the Northeast) by Dirt Productions.
BBQ Brethren, forum heavy into comp cooking.