itboglesthemind wrote:thereby taking advantage of the increased compound interest from the higher balance.
This is not a true statement. There is no "increased compound interest" having the money in one account versus splitting the money across multiple accounts.
Otherwise, your plan is reasonable. I have chosen to have one 529 per child. I don't see having multiple accounts as a big deal. They are very easy to maintain. If for some reason my DW and I should die, then it would be clear how much money each child got. This would not be the case in your situation. Hopefully, the odds of encountering this case is small enough that it really doesn't matter.