You need to ask someone if people (even pros) are allowed to go out of order, who those people are, and what the expectation is. People with multiple rides often have it built into the schedule already so they have time between horses and if random trainers start coming up to you asking if susy can get bumped a few rides down you’re in for a long day. Trainers often have people helping and I’ve seen plenty of trainers who deal with close ride times by having someone holding the next ride and then they practically vault from one to the other.
I was at a show where a trainer tried to bump me up by several riders (all her own) so she’d have more time to coach all of them. She had already bumped me down by 15 minutes waiting at the ingate for stadium because her students were ready to go and I went from being next in line for stadium to standing around on my foaming at the mouth horse.
I almost burst into tears, I was nervous enough already had just gotten down to warm up since I had 20 minutes and this trainer wasn’t exactly nice about it but the ring steward looked at that trainer and said “I have never had anyone go late in 10 years of being a ring steward and I don’t plan on starting with you. Get your students to the start box on time and in order or tell them to go back to the barn.”
