The "delta breaker" is a strange beast, no longer made, and not relevant here. It's best to dodge that part of the your question entirely. (If you're really curious, stop by the chat room tonight; some of the regular participants actually have them, and can better explain them to us).
Your point is a good one, though. The illustration in the handbook (210.2) presumes that one 'hot' leg will be serving both halves of the receptacle, so they will both be shut off by the same two-pole breaker.
What if you want the two halves to be on completely different circuits?
The ban you mention (found at 384 in pre-2002 editions) appears in a paragraph devoted specifically to the delta breaker. Oddly enough, it appears that the delta breaker was intended for this exact situation - and it's no longer allowed.
Now ... if I may go off on a slight tangent for a moment ...
I've tried to find replacement receptacles like the ones you pictured, and have had some difficulty. I suspect that, like two-prong receptacles, that this arrangement is no longer allowed - except for replacement / maintenance purposes. For all I know, they might not be UL listed any more (won't be the first such situation).
Returning to your question ... I think you are limited by the code to two solutions:
1) Tying a single pole and a two pole breaker together with a handle tie (if you can!); and,
2) Having a separate three pole disconnect switch.
Off the cuff, this looks like a very good issue to address with a proposal to the NEC committee, for the next edition!
