Ohio Scott -- here would be my 2 cents worth. I am admittedly conservative when it comes to controlling panfish species. Others worry more about their prey base, especially the southern pondmeisters, while I worry first about my predator base. I'm not certain I am right - it's just the way I was "raised" in pond management.
So, my concern over your stocking plan is this: I don't beleive smallmouth bass can control all those panfishes (especially bluegill and yellow perch). Smallies do NOT have the predation capabilities of largemouth bass, even in a small pond like yours (2/3 acre).
So, I would encourage you to definitely add the HSB to your combination for additional predators. While HSB are more effective as open-water predators, your pond is small enough that they'll interact with the other fishes simply because of pond size.
As I said, I'll admit that I'm conservative in pond management. If it was me, I'd want to play it safe and add the second predator. I'd also want to get the predators established as soon as possible, given the "head start" of the bluegills.
