Xcel tends to score higher than JO. My DD competed Silver for a year then switched to L4. Her podium placements were still the same, but she was getting there with much lower scores. She could easily hit a 37+ in Xcel but didn't get her first 37 in JO until L7. Also, if it was the first meet of the season, it's possible you were seeing higher scores because girls were scoring out of that level. I've seen girls score out of both L4 and L5 at the same meet then they reappear a few months later when optional season begins.
Your DD is on a L8 training team. What does that progression look like at your gym? Are they fast tracked to get there ASAP? The JO program is progressive so I guess technically everyone is on a L10 training team because that is the ultimate goal of the JO program. I'm kidding but I do find it interesting that your gym calls it a L8 training group. If they are being fast tracked, then there are some details in the routines that could be overlooked because they don't matter. Other details do matter though. The purpose of compulsory levels is to set the athlete up for success in the higher levels. The emphasis on form and details will help the athlete get to higher levels safely. Some of the skills in compulsory routines are actually drills to get them ready for skills that take a couple years to master. Look to see how athletes are doing at your gym in L9 and L10. Are they competitive? Are they healthy? Do girls qualify for regionals, easterns/westerns and nationals? My DD trained 9 hours/week at L4. It's appropriate, but on the lower end of the spectrum. In your case, I'd be concerned about what the ramp up to L8 hours looks like and the percentage of time spent on strength, conditioning, flex and uptraining. If your DD's coach forgoes 'little details' in L4 because they aren't important, then I'd want to know that the training program supports this and that she's not at a higher risk for injury later on.