that's right. But you can also teach them a "walk ahead" with halter and lead rope only. Or do some ground-driving - making sure that they carry a girth with loops or rings along the topline to keep the driving lines in the right place. Ground-driving might be the best way to teach them to walk ahead and with the girth you make also a clear distinction between normal leading, packing and driving.
I also like doing travois work in preparation for pulling.
I also like doing travois work in preparation for pulling.