yes that is true, if more than 1 person worked on the quilt it is no longer an individual body of work.
you would enter as a group and be judged as a group. if you win money that would have to be worked out in advance how the group wishes to divide up the funds.
when you request someone to quilt your top to show standards either they will tell you no or they will ask for much more money then they typically charge to quilt a top - show standards are much higher than what someone typically does on a regular basis.
one wrong stitch and you've lost.