Hi
In most of my projects, a common profit center is defaulted to the Bank Account through FAGL3KEH in a new gl environment. This is because the payment function had been centralized and so it was booked to the corporate profit center which was also a common profit center.
However, it would again depend on your business requirements as to how they would like to see the profit center reporting. You may look at a substitution through an exit to default the profit center for the main bank gl.
Regards
Sanil