You should know that 2 circuits that share the neutral are required to have the breaker handles tied together. Example: a two pole breaker with a common handle. Having two separate breakers apart from each other where the handles can't be tied together is a code violation.
Wish the people that wired my house in Rapid City knew that. I had a circuit where each the top and bottom outlet in each duplex receptacle was on a separate circuit. I needed to do some work on one outlet and got bit because it never occurred to me that someone would wire that way. I guess they got a good deal on some 12/3 wire.
Doug in SW IA