Not sure if there is truth to this but ppl mention that 9 is stronger than 10 in terms of the chain.
The standard cc comes with a crank that allows you to add/bolt on a granny gear if you needed to in the future?? although you might need a new bb and front derailleur.
Are you opposed to barcons?

I have a 1x9 shimergo setup. Campy Ergo with shimano 9 speed cassette. Works great.