Seniority should definetly not be used to consider a driver, well at least in my opinion.
For our team, we had "Driver trails" where anyone who wanted to drive showed up,a nd we practiced. We also try out different combinations of drivers during off-season comps.
I was chosen for driver because of my skill, and calmness under pressure. Our controler is my twin brother, which actually works out really well, because we obviously know how to work together (we've been doing so for the last 16 years), and because we see each other every day. So basically, if you have a set of twins on your team, try them out
