I would say don't do it for two reasons. First, the styles are very different (as mentioned above) and the hoppy flavor from the Dead Guy will probably be assertive enough to impart some flavor in a stout. Second, it is dry yeast, which means it is cheap and doesn't need a starter. It seems to me that the biggest reason to pitch onto a yeast cake would be to save money and/or time, and you wouldn't be doing much of either one.
Primary 1) Empty
Secondary 1a-f) - 2 gallons Traditional Mead, 4 Gallons Melomel, 2) Wee Heavy Widgeon Ale, 3) Pintail Pale Ale
Bottled - Amber Ale, TheJadedDog's All Amarillo IPA x2, Apfelwine, Wit Bier, Stout, Pintail Pale Ale (V1-Cascade, V2-Amarillo), Graff