Staple polyculture idea

I've got this idea for a two-year crop rotation polyculture-based way to grow potatoes, buckwheat and amaranth, along with some other, minor crops. The species I'd like in there are as follows:
-Potato (Solanum tuberosum)
-Buckwheat (Fagopyrum esculentum)
-Grain amaranth (Amaranthus spp)
-Creeping bellflower (Campanula rapunculoides)
-Marsh woundwort (Stachys palustris)
-Aardaker (Lathyrus tuberosus)
Plus maybe an additional nitrogen fixer, like white clover (Trifolium repens).

The core of the system would be potato, buckwheat, amaranth and creeping bellflower. Every patch of the polyculture would alternate between "root years" and "grain years".

The root year starts with planting potatoes into a bed with an established population of creeping bellflower (and possibly other wild-type perennial root vegetables). Mulching is used to suppress the bellflower closest to each potato plant. In the autumn of the root year, the potatoes and the bellflower roots are harvested. Some bellflower roots will remain in the ground as it is nearly impossible to kill creeping bellflower. The ground is lightly mulched.

The grain year starts with pushing aside remaining mulch and sowing buckwheat and amaranth in the soil disturbed by last year's root harvest. Creeping bellflower plants will start popping up. Their leaves are harvested for food so that they don't shade out the buckwheat and amaranth seedlings. Once the buckwheat and amaranth are tall enough to manage, the harvest of bellflower leaves stops, and the bellflower forms a groundcover under the taller grain crops. In the autumn, the grain crops are harvested, and the ground mulched. Repeat.

So, what do you all think? Possible? A terrible idea? Modifications needed? I'm planning to build a couple of small beds for trying it out this summer.