I know, an actuary who hates to assume - now there's the definition of irony!
I am trying to better understand the question being tossed out for discussion.
Are you contemplating a scenario where a single employer would sponsor both a DB plan , and a DC plan (for younger participants only), offsetting the DB plan by benefits accruing under the DC, and then cross-testing the result to show it is non-discriminatory?
I suppose that this would work, but I can think of a few messy situations that might occur.......
One of the few advantages of a 412(i) over a traditional DB is that the funding can be smoothed out considerably by funding with insurance or annuities. If the DB benefit is now offset by the DC plan, and there are sudden investment gains or losses in the DC accounts, the funding patterns could become somewhat erratic.
Anyway, before I get carried away with too much discussion, can you tell me if I am clued in to the actual topic?