There are different reasons for controlled starts.
One ride we had some pavement to travel over, about 1/2 mile out of camp, so we
were all walked to that point, then let loose. Other rides might have a tricky,
hard to follow section, and if the ride starts in the dark, they need someone
who knows the way. Also, I've been to rides where a gate must me opened and
closed for the horses. So find out the reason for the controlled start, so you
know if you need to be with the group to pass through a gate, or an unmarked
section of trail etc. I try to start about 10 min. after the main start
group with new horses, to let everyone go on ahead, and I can better ride
my own ride. But indeed, I am AT the start, to check in with the number taker
before the regular start time. In fact, I like to let my horse watch them all
take off like the start of the Kentucky Derby, while we hang out and stay calm,
then walk out of camp 10 min. later. Speed can be added later to a horse
if "racing" is what you want. But trying to teach them to stay calm and focused
is much more difficult if they were let to "run" at some of their first
rides.
I think that for the most part, smaller starting
groups, controlled or not controlled are over all, more "controlled"and calm.
The larger the group, the more I see those who feel the urge to race
and take off quicker. Maybe it is the mentality that they have more folks
to get ahead of, so they do it right away out of the starting gate.