Flip a coin!
To be clear, what the VP brings to the table is not so much help with governance but VOTERS. The idea is party unity.
The recent Pew poll said nearly 25% of Hillary's supporters would defect if Obama were the nominee, which is a troubling number. How many of those people would vote for an Obama/Clinton ticket in November? I have no idea, but that's the relevant question. You can't worry about power sharing in the WH if you don't get there.