rio:bhp carrying third party iron ore

What Rio has done has been quite predictable and an obvious ploy. And I think the market is getting the implications of the IOH deal seriously wrong in thinking this is opening up the BHP/Rio rail networks to small independent iron ore hopefuls. IMO it is in fact the exact opposite. BHP/Rio have full railways but have ignorant politicians telling them that they must carry other people's ore which is just a nice piece of socialist thinking from school teachers/journalist who have zero business experience and could not run a corner shop let alone an iron ore mine. So what has Rio done? Offered to take a miniscule amount of IOH's ore (a deal between old time mates) and can now say - "Well we have done what you asked of us .... but sorry guys - our railway is now full so we can't carry anyone else's ore". Now BHP will surely scurry around and do a similar deal IMO. With whom? In all probability UMC as their new line will cross Railway towards Jumbo whilst their existing line is right there as well - and UMC has what the steel buyers want - DSO.