Yeah, it is fine to use TuiZhang in this way. Becasue of the position and use of the elbow it is still that 'slicing' power I am talking about. It cuts while moving forewards. it could not just shoot in like a punch.
The WC punch is not like Shaolins pubch but your right closer to tuizhang or shaolins hammer.
Shaolins Hammer ZaChui is slightly complex. It can be horizontal like in Xiexing or vertical. It leads with the crushing elbow, once interaction is made it changes to a hammer down fist, once interaction is made again it shoots foreward as a punch. It often does all those motions at once however in a small space though it has the potential to be large.