Can I put someones actual name in the list of potential beneficiaries?
Yes, you can. You would only need to do this if that person does not already fall into the list of discretionary beneficiaries, for example the clients partner if they are not married to each other. Putting the name of someone who is already within one of the categories of beneficiary would not give them any greater rights or priority over other beneficiaries than they already have, so is not necessary.