very true. Control comes always first.
The marking in the ball indicator was not to be used below the red line, if I recall correctly. Or perhaps it was the blue line.
Upon engine failure, control was primary and performance secondary. If performance was too bad and speed was near red line... Retarding the live and putting the airplane back on the runway was the thing to do. We never used limiting runways, of course, but those Senecas would not make anywhere near the performance on the POH charts.
I deemed the twins as more dangerous that singles in approach, landing and take off phases. In the cruise, though, is better to have two.