Ok dont get to excited there is a bit of a twist!
I created an Arsenal B team and it didnt work in England. So what I tried is entering the B team in a spanish league because they use B teams and it worked!
I put the Arsenal B team in the Spanish second division B4 and played out one season. There was no problems that occured. The B team finished 15th and then at the start of the second season where moved to division B2.
The only things I can think of that my cause a problem is if the B team got to such a quality that they qualified for Europe, not sure how that stands. Also if the B team was relegated from a playable Spanish league. Would the computer recognise them as a spanish team or a English team, if its English then it would go back to the original problem and they wouldnt get promoted again.
Im going to start my new career game using this method, so I hope there is no long term problems

If anyone trys this and finds any problems or issues post back so I can avoid it