I think the only way that really works is that your community colleges have to be able to teach your basic engineering core courses well. Not sure that is really the case in Iowa. They are always trying to get my brothers, who are retired high school math teachers, to teach at the community colleges and they both only have Bachelor's degrees.
Where is that at? Here at Kirkwood we can't teach transfer level courses unless we have 18 graduate level credits in the field. If it's career tech, different story. Instructors here have at minimum a MS, one has a PhD.
A lot of the dual enrollment is starting to fall away due to the new higher learning commission requirements for accreditation. I'm starting to see more "regional centers" pop up where you get instructors closer to the population they serve.You can save money by bulking up on dual enrollment and AP classes in high school. All of my kids are doing that. If I remember right, I think maybe they got to keep their dual enrollment class grades as well (these are classes where they got both high school and community college credit because the teacher in their high school had a masters and could teach the community college class in the high school). On AP classes, I think they got credit but did not get to have the grade in their GPA.
A lot of kids will go to ISU and go ahead and take the class they passed the AP test on, just to get an easy grade and wreck the curve. Son said he saw a lot of that in things like Calc III. My kids have just elected to move on to the next class and not retake something they took in high school.