So? Baines got an "assist" for his missed penalty against Stoke because it rebounded off the post and back off Given.
Goals and assist stats tell us Osman has been better than Iniesta for the past 10 years.
Baines didn't get anything for that penalty, weirdly enough.
An assist is only actually counted as an assist when it is team-mate to team-mate, IIRC.
Del really provided about 12 goals last season I think, but a lot of his crosses took little deflections etc, so they don't count for him.
Which, like you said with the Osman example, is why you can't just judge them on that alone.