Returns will all be relatively close. Seek out the tax breaks, they're significant.

Don't be chasing the tax beak. Seek out returns. Compare the returns you're getting with the returns elsewhere. If elsewhere equals a higher ROI all things considered (including the tax break) go elsewhere. Pretty simple.

Do DC. Contribute $20k per kid today. 2 years after, transfer funds to a lower cost fund. Take $4,000 per kid tax break every year for 5 years.

I have 4 kids.
Child A-529 DC in my name. We get the 4000/y tax break
Child B-DC 529 in DH name for tax break
Now I am setting up 529s for children C & D.
I'm trying to figure out if it makes sense to do a non-DC 529 for either of them, as if we Max all of them out tax-break wise, yearly, will it matter? I'm thinking child D is a DC 529 in my name to extend taxbreaks, but does it make sense to do C in a higher performing one since I don't think we will benefit from the tax break of DC with that one.
A and B are 2years apart
B and C are 3 yrs apart
C and D are 4 years apart.

I feel as if this should be clear but I'm completely stumped.