Thank you everybody for your input. This has helped me, if for no other reason than to bounce it off of you, and know I'm not way out in left field - and hear that the equivalent footing method is logical (if used in a logical manner).
I feel comfortable using a large enough area to resist overturning, as long as that area checks out for the cantilever. Toad, to your basketball hoop analogy, I would say if your driveway was 24" thick with reinforcement, you could use a pretty large area to prevent overturning. In other words, as long as I can get the cantilever to check out, that distance/area would be okay to use in resisting the overturning. That's my thought process. Let me know if you disagree.
I'm ending up making the plate a little bigger so the numbers look a little better on paper, and I'm not relying too much on my engineering judgement. That way if someone screwed up the rebar 30 years ago, or something, and the slab starts cracking, I can numerically prove that what I designed, given my parameters.