The ring spacings are incorrect and you also have to be careful with the physical thickness of the rings because they are supported on two sides.
The ring spacing is set by where the teeth are machined on the section of the material - so on a 9s ring, the teeth are pretty much in the middle. On a 10s they are dished towards the big ring but there is still a narrow shoulder towards the big ring "side". 11s chainrings, the teeth are machined flush with the surface closest to the big ring. This affects how the front mech works and the probability of chain drop going from big to small ring, so it's not recommended to use 11s rings with anything other than a full 11s system. Additionally, on a compact, because the rings are physically closer to each other, the wider 10s chain tends to catch on the back of the big ring if you are cross-chained on the small - this can lead to an effect that looks like chain suck which in turn can damage the paintwork of your frame, the chain, the chainring or all three - so it's a pretty bad idea all round.
Some Campag 10s cranksets used thinner rings than others which puts a "wriggle" in the ring behind the crank if the chainring thicknesses don't match - that can lead to the chain dropping off the big ring onto the small if you are cross chained and the effect gets worse the more worn the system gets.