You have more then just the ribs to be concerned with . The head is off-shape (looks too pointy) and the bones of the extremities are too blocky (they are larger at the ends and taper in the middle) and in general almost none of your bones are anatomically correct in detail .
But since you were worried about the ribs I marked up a rough shape you might want to follow in a screen shot along with a couple of other major bones which are incorrect .
For the ribs:
from the front view : the most important thing you are missing is the inter-costal arch - this is a series of cartilage that defines the lower portion of the ribs from rib 6 to rib 10 - and yes it usually looks like an arch . And in general the outer curve that the ribs indicate also has an arch to it almost like and egg with its pointed end upwards . Also the clavicle (collar bone) is too high .
from the back : ribs 11 and 12 do not connect to the main body of ribs in fact they “float” in the muscles of the back . Also at bottm is a rough shape of the ribs from top at its widest point (usually @ rib 7) .
from side : you need more volume - push out the sternum to about where I have drawn it . Also the ribs do not curve up to attach to the sternum - when looked at from the side they seem almost straight and “radiate” towards the intercostal arch .
For the hip bone : in general it is too small and the socket for the femur is too high .The top part of the hip bone (the illiac crest) is almost twice the size of the lower part .
For the shoulder blade (scapula) : the biggest thig you are missing is the spine of scapula anatomically - that is the part that actually makes a socket for the humerus - it attaches to the clavicle in the front - so your upper arm bone (humerus) should be below that . And it tapers out of the face of the scapula at almost 90 degrees . And the whole scapula rotates by the way - around 30 degrees max from its rest position (arms at side to max of arms over head) - so you should give it a tilt of +10 degrees in that T pose .
I hope this gives you some ideas as to improving your model …
BTW the backbones of the upper torso aren’t called “Dorsal” they are called “Thorasic” - I don’t know if there were other name errors but that one I noticed …
Also you might not want the back armature bones to be connected like that (have them offset and snap-to grid or parallel to Z-axis) - that might be causing the irregular rib movements (though adding the intercostal arch (armature)bone(s) might help that too) and make the “rib empties” interact somehow with the spine bones …