Fitness classes to utilize gym space when there are no martial arts classes scheduled

[jjll]

I'm a martial arts school owner and am wanting to utilize my gym space that sets empty all morning and early afternoon. My martial arts classes don't start until 3:00 and run into the evening hours. I am going to add group fitness classes during the "empty hours", which are all morning until 3:00, and was wondering if anyone who has done this has any input and/or advice regarding this. I'm wondering what's the best method of hiring/compensating a fitness instructor -- charge a flat fee rent, charge "rent" by the hour, pay them outright per hour as an employee, pay as an independent contractor with a percentage split to encourage them to fill their classes. I will be booking and taking payments for the fitness classes through my school management software. I will be advertising for them on my website, in signage, etc. I will be providing use of my equipment (the instructor may bring his/her own equipment in addition to mine). I want to know what has worked in the past for any of you and if you can offer some advice. Thanks in advance!