His athleticism is sorely missed, let alone his basketball IQ. GR3 was great at finding passing lanes and even better at improvising when the passing lane wasn't there.
I went back and watched some clips you had posted in another thread and he could score effortlessly 10 feet and in.
We got away with playing him at the 4 defensively because he had the athleticism and strength to make up for the height advantage. Unfortunately, Irvin has neither and is more of a 3 even though he's a couple inches taller than GR3.