How to grant account access, when the account has two different sites belong different territory

Hi Team,

Based on the attached we have implemented restricts all accounts and access groups..

Now we have requirement to implement to below scenario,

If Account has two different sites (Site 1 and Site 2) belongs to two different territories (E1 and E2), but the primary site is Site 1.

Site 1 - Postal code belongs to E1

Site 2- Postal code belongs to E2

Based on the assignment, the site 1 is primary, E1 will be assigned to the account. E1 resource will be having the access to those accounts.

But E2 also needs the access, how can be achieve this.. requirement instead manually work to add the team members manually