Dont most tanks already have smoke?
The designation "smokelayer" is a bit misleading. Its a 15cm Nebelwerfer, and that that was translated literally instead of using it just like a name (as the English Wikipedia entry does)
The 15cm Nebelwerfer was initially designed to throw smoke and other chemical shells, but mainly fired HE shells during the war.
The combination of a 15cm Nebelwerfer 41 and a Maultier (Mule) was called Panzerwerfer 42 (SdKfz 4/1)