If the Eastern Agricultural Complex was fully develop it would as good as Amazonian agriculture. Only Eastern Agricultural Complex crops fully develop in OTL were Squash (Cucurbita pepo), gourds, and sunflowes. Little barley and Maygrass would give them grains to make flour. Erect knotweed and goosefoot give you leafy vegetables. Sumpweed gives you edible seeds rich in oil like sumflowers. If add Pecans and American chestnuts plus Maple sugar and syrup. Would if you almost compete agricultural system for North America.
I did a scenario based on this idea for my AH Newsletters a while back. I'm not sure if I posted it here. I had the old Eastern Agricultural Complex crops developing earlier due to earlier selective breeding on the part of the local Indians. I agree that the crops involved could have had considerable potential given time, though I suspect that corn and beans would have become part of Eastern North American agriculture too.