Why Iron Duke was retained as the gunnery training ship

Why was Iron Duke retained as the training ship instead of Tiger?

Chatfield favored Iron Duke's gunnery associations and stability as a training platform, even though Tiger offered greater potential for a later combat reconstruction.

Iron Duke's appeal as a gunnery training ship combined practical suitability with naval tradition. Chatfield favored her connection with the Royal Navy's gunnery history and her service as Jellicoe's flagship. Her perceived stability also counted in her favor as a training platform. That role did not make a later combat reconstruction attractive, because her limited speed offered little return for the work. Tiger's speed and remaining hull life would have given a reconstruction different possibilities.