I don't think Carpenter will be there at 28. Carpneter alone is greater than Whitner. Dallas should just take the linebacker they want at 18 and not get greedy. I have a feeling there will be a long run at linebackers after Dallas picks.
I think you will be happy on draft day. The Cowboys will take a linebacker at 18...or they may trade down two or three slots if things fall right and still take a LB.