Its to do with their heights... sorry I didnt check but how tall are your guys? Im training a 6'6 and 6'7 in OD (sometimes a 6'10 guy!) and I am convinced in the long run it will be worth it (others might disagree) you have to be very patient indeed.
What are there current levels of OD? If you can get away with playing them there and still winning games maybe Passing training could be more optimal?