Personally, I think it's over kill. I cook exactly the same amount of meat for competitions. I put a probe in one of the briskets (closest to the heat) and a probe in one of the butts just as a general gauge of how things are going. I use my Thermapen when things get close because I not only want to have an accurate temperature, I also want to feel the probe slide in.
I don't use a thermometer for ribs or chicken. I go by time and appearance for the chicken and time, appearance and feel on the ribs. Sometimes too much information will only confuse you more. Especially with briskets!!!
Good luck and Merry Christmas!
Mister Bob, Pitmaster - Bob's Hogs. KCBS CBJ #31759 - IMBAS Certified MOINK Baller