Good question Ken Ashcroft. You may get 2 answers: No and Yes.
The team of Dr Strange, Namor and Hulk (no SS) first appeared in Marvel Feature stories (3 in total, if I remember correctly) as the Defenders.
However, when the official Defenders book started shortly thereafter, Silver Surfer was indeed present. Within a few issues, Valkyrie became the fifth member of the Defenders.