It depends who the plot point says must be in that specific angle.
For example: If the angle says Attack Nash (Major Catalyst), Hall (Major Catalyst), Sting (Major Catalyst), as long as you pick an attack angle where these three are in those roles, you can use as many other people as you like. IF you only use 2 out of those 3, then the angle will not work.
Read the plot point carefully and make sure you have the people required for that plot point in an angle that matches the requirements.
Does anyone have any updated angel that they have created? I created some myself but accidentally deleted them.