While most of the Tweety-Sylvester cartoons have Tweety brutally inflict pain on Sylvester or see the putty tat attacked by Hector the bulldog, "Greedy for Tweety" throws a wrench in the works by having all three get injured at once. When the trio runs into a busy street and each member ends up with a broken leg - does minuscule little Tweety have enough of a leg to actually get broken? - they get taken to the hospital with Granny as the nurse. Sure enough, Sylvester is still fixated on devouring Tweety (even if it means abusing Hector), while Hector is intent on protecting the little guy (even if it means abusing Sylvester).
Many years ago, I saw this cartoon as part of the compilation film "Daffy Duck's Movie: Fantastic Island". But I'd forgotten some of the coolest scenes (namely the X-ray and the hammer-wielding mouse). As for the idea of Sylvester and Hector fanatically continuing their battle while Tweety sensibly tries to get some rest, maybe that's an allusion to the Cold War: the two superpowers sought to destroy each other while smaller, humbler countries tried to settle down. You know what they say: when all you have is a hammer, everything looks like a nail.
OK, so I probably went a little far in trying to analyze this cartoon. The overall point is that "Greedy for Tweety" is truly a fine one. Friz Freleng always had some great ideas.