When doing shihonage as a cut (the first cut)
your left foot crosses the centerline ,with the heel pointing slightly forwards,for a split second ,
if you make this step too narrow you will not get out of
ukes way ,and you will be unstable even if it is only a split second.
If the step is too narrow you will have difficulty in taking ukes balance before the turn ,so if the step is wide enough you will probably also find that itīs easier to take uke's balance,
remember to keep contact - there should be no "air" between you and ukes arm when you turn.
I say this from a Nishio-style shihonage,footwork differs in different styles ,so I hope you can use this information.
yours - Chr.B.