Next time you see a late model C4, notice how the front wheels sit inbound of the wheel well lip vs. a more flush rear fit. Then, look at a 85-90 model and notice how all four wheels have about the same lip to wheel edge fitment.
The offset front vs. rear wheel on the late C4 models (and CE) do indeed reflect how they also have different sized tires.
What year is your car?
You can do the wider wheel all the way around, but have to watch your tire size. I would suggest running the 275 40 ZR 17 in the front on the wide wheel, and the 285 rear tire that is stock on the back of a CE.
If you go with the more narrow wheel all the way around, I think it will look silly as the rear wheels will be sucked up under the fender lip.
I saw a CE the other day that a fellow must have rotated the tires without paying any attention to what he was doing. It had the small narrow ones on the rear and the beefy ones on the front. It looked stupid (mostly because of the fat ones on the front).
Much of this depends on what year model you have. The most trick thing I have ever seen is putting the GS or ZR1 rear rims on a 84-87 model, then putting the 9.5" front rims on the 84-87 with the wheel adapters. That makes one heck of a beefy look from behind, and puts the front tires nice and flush looking with the wheel lip.