Ideally, I'd love to have a 3-3-3-3 and then just redshirt one player every year to maintain it. If I wind up going 4-2-4-2 or something, it's not the end of the world. The balanced approach is, in my opinion, best for people trying to maintain a quality program for the long haul. You just need to keep an eye to the future if you redshirt players and, when necessary, grab a JUCO to re-balance the classes if things start to get out of whack.
The off-balance approach is better if you're looking to move up a division. Stack two classes, wait for them to get upperclass status and then apply for positions after they've had their peak year.