I've got a flyback transformer circuit, that was designed by a firm and they tended to over-engineer things (this is in a commercial project).
I re-laid out their circuit and on the primary end of the flyback circuit they have both an RC snubber and a TVS Diode protecting a MOSFET from transient voltages and for inductive loads when the MOSFET closes.
I've actually torture-tested this circuit and removed both the snubber and TVS diode at the same time and no magic smoke pours out of the FET as I am applying the maximum current with a PWM pulse to the flyback transformer (ie. it is receiving current, right below the saturation point and the peak duty cycle -- ie. transformer torture test).
Is there a reason you would want both, do they seem superfluous?
I could see a case where perhaps the RC snubber is protecting the MOSFET, and even though the flyback circuit can run for hours you are prematurely damaging the MOSFET by removing the snubber?
I really don't see the case so much for the TVS Diode... I have no idea what a transient voltage would look like in a transformer failure, but if the transformer fails the board is pretty much trashed anyway from a product perspective.