Are you sure Apple does their accounting in that way?
Do you have a reason to believe they don’t? We’re not talking about some weird or obscure custom, it’s just basic business ideas.
Apple famously doesn't have conventional business units.
https://www.apple.com/careers/pdf/HBR_How_Apple_Is_Organized...
I think the burden of evidence is with you in this case. It doesn't make sense for Apple to do their accounting with such a method.