The 'standard' power curve being discussed here isn't really relevant, is it? Induced drag has to do with tip vortices and recirculating flow, surely, whereas in auto there is none of that, just some reduction in rate of descent airflow a la the 'parachute' effect Crab mentioned, unless I'm sadly mistaken (which is entirely possible of course).
In a 60 kt auto you might come down at 1500 - 1700 fpm, say, but there's no way you're doing 3400 fpm at zero speed, is there? More like the extra 300 fpm or so sounds about right.