In the 5 fists, do you deliver your punch simultaneous with your leading step or trailing step?

I recently had a discussion with a Xing Yi practitioner from another school who delivers with the leading while I use the trailing.

The body seems to be able to use spiral/torqueing energy and body mechanics more efficiently with rear step delivery. Also, the front foot does not need to be brought up as high and the stomping can be reduced. This seems to make the front foot stay closer to the ground in more of the Bagua tradition.