Since most babies like Pichu promo, igglybuf(both), and cleffa(both) dont
have attacks that do damage attaching steel energy to them would have any
affect  on there attack and steel energy would give protection against baby
killers like murkrow.
Because steel energy reads damage done to pokemon steel energy is attached to
is reduced by 10 and if its not a steel type the pokemon steel energy is
attached to reduces its attack by 10. So thats why its ideal to use these on
baby pokemon that don't do damage. So putting steel energy on a baby is like
making a bigger wall than it already is.

By: Ramon Arispe