For most dentists three or more hygienists is too many but there are those dentists who make it work. To make it work requires that the dentist and hygienists are in coordination so that appointments are as smooth as silk.
You will also need to ensure you have excellent scheduling protocols in place and are efficient and effective at communicating with patients.
Whether you have one, two or three or more hygienists you don't want to be hurried when doing hygiene exams as you will miss opportunities to present treatment. If you are hurried then add extra time to the schedule for exams or start looking for an associate.
Doing the exam before the end of the hygiene appointment can also be very helpful.
Of course you could always get some roller skates.