If you feel comfortable in coaching participants doing different exercises with that size group, you could do a small circuit with various timed exercise stations. There any any number of options for this. Your background has strength, Pilates, and Yoga, so you could do a station with one or two of these (example, 8 on TRX and 8 doing an exercise on a mat or with weights). That way, all class members remain active at a station while “waiting their turn”.
If you have more than 16, you could just add another exercise station and rotate the participants through.
Hope this helps.