Even somewhat experienced shooters can have issues under match pressure. (When the buzzer goes off you are half as smart as you were before.)
Inviting a total newbie to a match to shoot I think is a setup for less than optimum results. The newbie will try to win it due to adrenaline and the regulars will try to help but be ineffective in that environment because the match must roll on and they can't practice what the newbie needs help with.
I think new shooter orientations and several practice sessions simulating some of the things found in matches for newbies go a long way to setting the newbies on the right track.