To that very real possibility, I say, "So?"
"But I can get him if I move up. That will only cost me my second round pick this year and my first next year. And I know, without a doubt, that he will be worth it." you say. "On second thought, that is a lot to give up, and I know I have just as good a chance with a couple of guys ten or fifteen picks later as I do with the hand I have been dealt at sixteen, so I think I would be better off trading down."
To both of those scenarios, I say, "Where have you been getting your information?"
How do you know that cat is going to be good enough for you to mortgage your future by trading up? Or why do you believe that you have just as good a chance of hitting a home run with second and third round picks as you do with that one sitting smack-dab in the middle of the first round? Why? Every slot you move down increases the chance your pick will be a bust. Every time you move up you reduce the number of chances you have to stock your team with solid players at other positions.
My suggestion: break away from the herd at BTB. If people who do this stuff for a living disagree on who the future pro-bowlers are, why do you think people here who have never even spoken to a single one of these players, up close and personal, can get it right?
Mocks are a lot of fun, but don't take them too seriously. They mean absolutely nothing in the long run. How do you really know that Aaron Donald will be a better pro than Ra'Shede Hageman? Three months ago, who was the higher rated Quarterback, Johnny Manziel or Teddy Bridgewater? Neither of them have played a game since then. And if you think the Cowboys success over the next couple of years depends on whether Anthony Barr will be there at number sixteen, and you just know he is going in the top ten, well, maybe you are just looking at the wrong mocks. Maybe you should try some that are a little different from what you see here on BTB day after day. Try one like these, for example.