Unique Visitors count in Adobe Analytics depend upon your implementation methodology.
You may be using default persistent cookie based mechanism or using a custom implementation to set Visitor ID variable / re-writing the Adobe Analytics visitor identification cookie with your custom logic.
If the mechanism used inside business objects for setting Visitor ID is same / similar to Adobe Analytics one, then only it makes sense to compare the Unique Visitors count between the two tools.
Regards,
Saurabh Kumar.