Pommel Circles and cartwheel leading hands

[Klaws]

Hi,
Does anyone know why my son’s coach would tell him to lead pommel circles and cartwheels with the same side? Currently he leads cartwheels with his left leg but circles with his right hand. Apparently it has something to do with teaching round back handspring later? Any thoughts please? He’s just getting the hang of circles and now this. He’s just devastated.
Ta,
K