Well, when you come busting into a thread specifically about using pumps for open bath recirculation, and then brag about your chill times using a second IC as a pre-chiller when presumably using a garden hose as the input, what did you expect?
You could get even better performance by applying some of the techniques in this thread. It would require another pump like those discussed here, though.
Without adding a pump, your way is the preferred method. However, the pre-chiller doesn't increase performance much until the wort temp is within ~30F of tap temps. Up to that point when flow rates are high, it just uses up ice without really making any meaningful change to the water temps. If ice usage matters, leaving the pre-chiller out of the ice bath until needed will save your ice for when it is needed.
Here is a post with pictures and graphs-
https://www.homebrewtalk.com/f39/in...ump-idea-share-267132/index3.html#post3344808