Hi Keegan and Dawn,
as I look at your profile, you own a personal training company that has several trainers, and I assume that your questions pertains to that scenario.
As the others have pointed out, if you look for a company-wide consistent approach to personal training, then you should hire a rather novice trainer who would probably willing to adapt to any personal training approach that you want to have adhered to. On one hand, that can be of benefit to a trainer because novices rarely have a ‘training philosophy’. On the other hand, you may stunt his/her growth because they become exchangeable cookie-cutter personal trainers. That, however, would not be your problem as the person running the company.
A trainer with more years of experience will likely already have a training approach. This is of value if your company philosophy is outlined in broader terms and if you have room for many different training philosophies as long as the customers are happy.