A.Create one site for each office and each local bank.
B.Create one site for all offices. Create one site for all local banks.
C.Create one site for Amsterdam. Create one site for all branch office and all local banks.
D.Create one site for Amsterdam. Create one site for the Utercht brach office. Create one site for that Hague branch office. Place half the local banks in the utercht site and half the local banks in the Hague site.
E.Create one site for Amsterdam. Create one site for the Utercht brach office. Create one site for each local bank that has more than 50 users. Place all the other local banks in the Amsterdam Site.