Can we use 2 different CIGs for AN and B&I

• One of our customers has already integrated AN with S4 H thru CIG for SCC. Data Center Europe. The same AN has to be connected to the ECC system as well.
• For the same customer , B&I is now activated and when CIG is enabled it is pointing to US Data center , with a new P User. B&I should be connected to ECC. The CIG which is enabled is not the one which is in use for AN-S4 integration.

Questions...

• How can we use the same CIG for both AN ( SCC ) and B&I ? Ideally only CIG should be used to my knowledge for all Ariba Solutions.
• Can we use 2 different CIGs for AN and B&I?
• Why has it created 2 different CIGs here , is it because of 2 data centers?