User1: You should assign the Reader and Data Access role to User1. This role grants read access to Azure resources and data, including the data in any storage account1. This role is suitable for User1's task of viewing the data in any storage account, and it follows the principle of least privilege by not granting any write or delete permissions.
User2: You should assign the Storage Account Contributor role to User2. This role grants full access to manage storage accounts and their data, including the ability to assign roles in Azure RBAC2. This role is suitable for User2's task of assigning users the Contributor role for storage accounts, and it follows the principle of least privilege by not granting access to other types of resources.