OT a #4 has GOT to be a non-starter just on principle. Much like the QB situation, there isn't anyone available worthy of the pick. So while you might pick a QB even though the value isn't there, given how hard it is to pick QB's and how important the position is, it is LIKELY that there will be one or two QB's picked in the first 4 picks this year. You cannot do that with an OT, especially when you need a LT and the player you are looking at isn't physically ideal for the position.
I don't have a problem with Campbell or any of the other top names, or taking an OT first, just not at #4. If Hunter, Carter, or Graham are there you have to go with them. If OT is your presumptive need, then you HAVE to trade down.
I'm reading that while this is not a very deep draft at the "blue chip" level, it IS deep at the next level. There will be a lot of NFL starters taken on the 2nd day and it wouldn't hurt to have another shot at one.