Presumably you don't have a 14 x 12 hive you can move them into ? ... You can, however, put a super on a standard national box which will give you nearly a 14 x 12 and put the five frames from your nuc in there with a couple of standard national frames of foundation and dummy out the extra space, as they draw out the new national frames, add more national frames and gradually move the 14 x 12 frames to the outside and replace them with the standard nationals. You can work the 14 x 12's out gradually. Much kinder than a shook swarm. They might build a bit of free comb on the bottom of the nationals but you can trim it off and then when you have mostly nationals with the brood on .. you can get rid of the super and any remaining 14 x 12 frames.
Not that I can understand why you would want to move from the superior format of 14 x 12 to the inferior standard national - just my opinion of course.