Hello Shilpi,
As per my understanding and experience working in SAP CRM over a period of time:
Firstly Account Identification and Inbox are two different features if WEB IC, with respective distinct usages, design and architecture. So, i don't can be compared.
Secondly, Account identification is the first screen launched while user is logged on. Also, same is used to confirm customer manually and automatically from an inbound call or other means of communication. This make it a business critical screen and should not overloaded based on user intervention, by changing maximum hits for example.
Whereas, Inbox is more of data extraction on request (user action) or configuration. Flexibility is given to view more data.
I hope that helps.
Thanks,
Kapil