Typically, if I plan on doing any rides that require lockers for the day and if I get there early, I typically do the rides that require everything to be stowed away first thing, or at least relatively early.
Some of the locker areas can feel a little claustrophobic to me with the amount of people who can get in there. If it's relatively early it isn't much of a problem. Also, The Dragon Challenge while is outside (the locker area), it does not have nearly the amount of lockers of other rides that have a requirement to stow all belongings away (as this was made a requirement years after the ride was built), so I'd especially recommend doing that ride first (if you're planning on going on it), as you might be spending more time waiting to get to a locker than actually wait in line if you decide to go on that attraction later in the day.
Also, a thing to note is that the wands with the box do not fit well (or not at all depending on the wand) from what I heard, but the wands itself do. Someone could stay with the wands? However, if all the people go on the ride I guess that is a problem. Unless they'll do something like child swap, or in this case wand swap.