Don't listen to these idiots.
Just ask your TM and get clarity. Nobody is going to expect you to convert a total knee surgeon day one.
Ask what the pay will look like. If you get a guarantee for 6 months, start there, but get clarity on when it ends. If its 100% commission on new business, then move on. If it is a % on existing business, then ask for an average or even the numbers that the geography is handling. Your job, besides logistics and case coverage, will be to ask difficult questions - start now.
ZB isn't a bad place to work. Yes there are issues, but every company has them. Backorders, failed launch dates, bad managers are common in med device.
Good luck.