thank you for the compliment. you may be right that he is just doing to much arm work and still needs some. but as a greneral asumption it is not true that you always have to curl or do direct arm work for growth. there are a lot of bb'ers that get better arm growth with no direct bi work. they get plenty from deads, chins, and rows and doing the extra is the overkill. of course this does not apply to everyone. there are people who need lots o curls to get their bi's to grow. i see the problem with people with lagging arms usually turning out to be what i had suggested. but not everyone. i just suggest that as a start then if you see no improvement you can start adding small sessons rom there.
My biceps were genetically not that great...deads, rows and squats have helped develop my biceps def...however, they help develop the thickness and mass on my arms...I had to do some strict preachers and some barbell curls to get some peak and definition on those babies.