You should as about the ability of each other to see notes. And if they would read each others notes. That would be an important thing to bring up in a first session. That way you will know. Just because they work at the same place does not mean they have access to each others notes. And even if they have access, does not mean that they would read them. As for complaining about one to the other, that happens all the time. They would be professional and not get offended or tell the other person unless it is a team treatment situation. Good luck with the T search.