...according to the standards of that time, King Henry should have received his annullment and it was withheld for political purposes.

If he'd been given it, that would have been purely - and cynically - for political purposes. The "grounds" for any annullment were complete rubbish. However all that was the occasion rather than the reason for the split, which was basically to do with power and money, like most things - in this case all that monastic property waiting to be seized.