What you say is right, but many times correlated pairs dont mvoe with the same amount of pips, so in order to maximize profit, i traded both of the pairs, isntead of doubling the lots on one.
generalizing the concept: When to take advantage of correlated pairs? When the correlation fails
Althoguht this is not the thread to discuss about it, for anythign about it PM/skype me
Have a good one