Use case 1: I'm managing a project that includes sub-contractors who don't have a computer and I don't want them logging in, but I want to assign certain tasks to them, and I'll monitor them and update their progress and status

Use case 2: I'm managing a project that includes a functional team with rotating, nameless users and I don't want them logging in, but I want to assign certain tasks to them, and I'll monitor them and update their progress and status

In these Use cases? What should I do? (Microsoft Project let's me add people without them becoming users)