more info can be found at the original image (my main account): [link]
I've consulted several people and all have come to the same conclusion that Sardi does not need a true avian furcula (required in birds for respiratory processes as well as a brace against opposing forces while flapping the wings). Sardi has a diaphragm and a hybridized saurian/avian respiratory system as well as digestive system. The forearm structure and chest, the way I have them built around each other, will act in accordance with each other to brace the body against the massive forces at work with each wing beat (aka an overly modified furcula composing of arm/chest structure).
All of the other points made on the image should answer questions, but I can answer other questions that arise either way.
Huge thanks to *Foxchibi
for their extremely helpful advice and suggestions, *shartman
and Gregory S. Paul for their skeletal reconstructions, and as well as several ornithology manuals and other texts/articles that I scoured for information via books or internet sources.