Sure, pecs are big, important muscles simply because of their wide range of activity. But they also matter because they call a bunch of the surrounding muscles into actionâ€”namely the shoulders, back, and tricepsâ€”which makes any chest exercise a fantastic all-over upper-body movement.
Also, simply arrange your workout in a way that those other pushing muscles are completed after your chest session, never before. So it's "chest and shoulders," not "shoulders and chest." And if you train triceps on the same day you work chest, it's always chest, then triceps.