Possibly. But only in the worst case scenario. The guns were usually pulled by halftracks and other smaller vehicles. Why tie up a piece of already mobile artillery by strapping another weapon or supply trailer to it. The tanks would usually be tasked at all times with missions or defensive duties. The 88 on the tiger and the 75 on the panther could be employed to cover the towed artillery while it was displaced to a new area. If the tanks did pull any kind of trailer it was usually laden with fuel.
Ill have a look through some of my references to see what i can find though.