From what I read in both accident reports had the pilots known about MCAS unfortunately it would have had the same result.
Like many others I have practiced the Runaway Trim scenario in the simulator many times.
I would appear that in both accidents the pilots did carry out the Runaway Trim procedure however reinstated the Stab Cutoff switches when they could not control the aircraft,bearing in mind there where multiple cockpit warnings including the Speed trim and Stall Warning.
The Ethiopian accident report says the aircraft crashed at a speed of 460kts due to the pilots not reducing thrust after takeoff.
I believe that many errors occurred in both accidents, however in my experience the pilots I have flown with in the past would have been able to handle the situation.
Having a look at ET302, there were several problems exacerbating this beyond a simple sim exercise. The damaged AoA sensors had caused a continuous stick shaker that had activated immediately after take off for the duration of the flight. Multiple warning system activations for related system and GPWS alerts. Easy to mask a spinning trim wheel.
The first time the MCAS activated for 5 seconds the crew then manually trimmed Nose Up again, the second time it happened it was the lower houred FO who suggested using the Stab Trim Cutout switches (all of this happened within 30 seconds). However with all of this going on the Aircraft was still trimmed nose down to the extent they needed significant backforce on the control column to maintain level flight. Boeing's method of using a "rollercoaster" technique to recover from this situation had been deleted from their manuals decades ago. The crew made an error here and allowed the speed to build up and further increase the forces required to maintain level flight, whether this was caused by distraction by other alerts or their struggle to pitch the aircraft up, who knows?
But it got to the point where they felt they had no option but to re-engage the Stab Trim to attempt to maintain flight and then the final MCAS activation occurred.
Could the pilots have done things differently that would have saved them? No doubt, but it's easy to sit back and read the report and think you'd be able to recover easily. It's easy as well in the sim when you know you're about to have that failure and that failure alone, and you know exactly what you need to do. But in real life when it's among a multitude of failures your reaction might be worse. I think that's called being a Monday Morning Quarterback.