Madam Chair, another alternative would be to say that when you have a three-hour slot, you invite two witnesses to be there for the full three hours, and each one makes a five-minute presentation. You go around and you take your choice of whichever one you want to ask questions of. If you want to focus on one witness for three hours, you could do that.
That's a possible alternative. Otherwise, it's hard to say to the clerk to book this one and give them two hours, but give this one just one hour, or we'll use up that one slot for three hours. Do you know what I mean? You'll be able to establish your priorities.