Yes, you can assign as many licenses to the same account, just as you can purchase as many licenses to your account.
Having multiple licenses under one account can be useful with floating licenses to create a dedicated pool of floating licenses shared online within an organization or served through a centralized license server in a local network.
You can read about our Cloud-based floating license sharing setup here.
You can read this article on setting up a centralized license server here and this article on configuring your product to connect to it.
Named licenses can only be used by the account to which they are assigned. If you purchase multiple named licenses, you will need to use the my.chaos portal to add users to your Chaos Organization and assign them to individual users.