As far as I know the bonus amount for referals only applies to those directly recruited (ie one level down).

Therefore, the main account (the one with 10 BTC) will be earning a bonus to the account above (with virtually nothing in it).

I agree that this method will mean that your higher level accounts will complete quicker (but when they are complete the bonus is kicked further up), so I do not see the benefit of this. 

I would need to work through some more examples before I could agree or disagree though!