How many people have been killed by engine failures in single-engine turboprops?
How many people have been killed practicing engine failures in light twins?
I don't know. Do you? But I guess this Caravan accident alone outnumbers all piston twin training fatalities together:
https://aviation-safety.net/database...?id=19850929-0
Anyway, training accidents in twins (which are mostly caused by inexperienced/incompetent instructors) and engine failures in turbine singles have no statistical relation of any kind. Even if we had the figures to derive a statistic from them.