contacting potential coadvisors? I am currently applying for PhD scholarships using the following strategy:

Contact the potential supervisor via email (75% very positive replies so far).
Apply via the official way.

So far there was always only one supervisor listed for the projects I was interested in. Now, however, I came across an advert with 4 cosupervisors listed as well. What would be the proper etiquette for my first email? Should I put the cosupervisors in CC, write separate emails for them or leave them out entirely?
The university in question is in Prague in case this is relevant.
I emailed the main advisor today, putting the coadvisors in Cc. He wrote me a very positive response on the same day, also putting the coadvisors in Cc. So, at least in that part of the world, this seems to be the correct way to introduce yourself.