Joyce's 3 stoppages as an amateur were very different to Wilder's stoppages. Joyce first stoppage was to Joshua ending in the ref stopping the fight and he had a TKO loss to Beguerni in a fight where he took two standing 8 counts meaning he didn't even go down. Suffice to say Joyce's, poor defence combined with amateur boxing's tendency to stop fights if a fighter takes too many clean shots led to these two stoppages but they were nothing like Wilder's stoppages. The one time we know Joyce was definitely dropped was against Kuzmin where he took a monster shot that literally knocked him on his ass and he got up at 4 and didn't even look remotely hurt. Suffice to say in Joyce's 3 stoppage losses he's probably never looked genuinely hurt unlike Wilder.