In my limited flying experience, it's definitely approach and over the hedge speed which dictates the quality or otherwise of the landing. Carrying just a bit too much speed increases the float exponentially. Conversely, you need to be very ready with a good dollop of power if coming in slow with full flaps and you hit a bit of sink or get a bit low.
Overall, I'd say one is more likely to crack up in the long-term by tending to carry more airspeed ('for safety's sake') than practicing coming in a bit slower. You may well find it is approach speed which is the problem.
QDM