Short answer, yes, all things being equal, having a large group of recruitable L10s is a good situation that brings more exposure and interest than having only one athlete. It is ultra-rare, if at all, that these girls end up competing for the same spots. Remember its a two-party situation, and schools sometimes aren't interested in an athlete that is interested in them, and vice versa.
Long-answer/commentary, As several posters alluded to, while sitting at L8, L10 seems like a natural progression of things, it is not. Odds are you will lose at least 2-3 for a variety of reasons (injury, diminishing interest, inability to attain skills, family issues or move, take your pick). Compounding this, I think some dont fully realize how different the MIND-SET and the amount of work and effort training at L10 has to be. At least to become a recruitable athlete, like, "I can have multiple offers" type athlete. It is a problem that we have at our gym. It really has to become a "this is serious, this is my career, if presented with go to the friday night high school football game and miss practice, I am not missing practice, I dont care about the social high school structure" mind-set type thing. Almost as if training elite. One can make L10, do their thing and be fine and I am sure another 2-3 of that group will fall into that category. These might generate some interest, if they develop one particular speciality of interest, like Y1.5 vault, but probably not. Its the final 3-4 of the group that really grind that will generate the interest.
Two other points to make, one the coach really does make a difference, so if your gym does not have a well connected coach, it might not be a bunch of colleges banging on the door. Second, the recruiting journey is different for everyone, so there will probably be a cluster of 2-3 that come June 15th they are swamped with calls and have committed by Sept (Assuming this "super" group of L8 all translate to L10) but others will be recruited into next year and even others into their senior year after they have graduated. So that group of 10 will be spread out over 2 years of recruiting.