Why is the empennage design of this Lockheed 1049E so complicated?
Complicated is a matter of opinion and I wont address that specifically since its somewhat subjective. But the core of the question is "why did the L-1049E have 3 tails" which is a legitimate question for this site. 

The design was to allow the aircraft to fit in hangars of the time 


  A sleek fuselage, something like an elongated fish with smooth curves,
  featuring a circular cross-section, a snub nose, and a triple-fin
  tail. Triple tailfins were selected because a single tailfin would
  have been too tall to fit into typical hangars.


The L-1049E had tricycle style gear that was quite tall (for the time) and a standard single tail would have made the aircraft too large to fit into the hangars that most fields had. 

The above link also discusses that for a particular Military version ("WV-1") of the aircraft the lower section of the tails were extended to compensate for a radome being mounted on the top. This came along only a year into the design and the subsequent builds may have been a hold over. 

Weight as a result of the added rudders would not have been as much as you may expect since they were traditional fabric covered style surfaces