My uncle was on the second wave at Juno beach. He didn't talk much about the war, but he did mention training practices on English beaches. But never mentioned any deaths or serious injuries. Maybe there were training sessions that went reasonable well.
My uncle was in the second wave, stepping over bodies. But much of the resistance had been cleared. His training didn't seem to have covered this scenario. He thought everyone was given a general direction to go forward, and make up a strategy as they moved forward.
Yes, we should also remember the soldiers who died during the training.