Complex sentence: Huggins' claim to the characters and situations of "77 Sunset Strip" was strong, since he had created them in a series of 1940s novels and novellas, but his relationship to this, the first episode of the upcoming series, was comparatively weaker.
Split into simpler sentences: Huggins' claim to the characters and situations of "77 Sunset Strip" was strong, since he had created them in a series of 1940s novels and novellas. But his relationship to this, the first episode of the upcoming series, was comparatively weaker.