correct and what happens is the opposite of bouncy. Slower runners have more vertical movement up and down than elite level ones. When the hips are high and running at top speed the hamstrings and quads are not in conflict and are working as one due to the force coming from the hip like a pendulum. This can only be achieved with adequate hip height and is called Lombard’s paradox.
Also worth remembering CF described it as trying to make a wheel go fast, you actually achieve it best by skimming it with minimal contact as opposed to conscious push / pull, same with sprinting.