Cyclist positioning can help, but the cases cited are killings by truck drivers where ignorance, laziness and just lack of care were the factors. How do you deal with drunk drivers, some who can't even see, or, most often, just don't look for whatever reason?
I repeat: Cyclists riding up the left of trucks is NOT the reason cyclists are getting killed in London at least. Inappropriate vehicles for the situation, ill-equipped vehicles, or incompetent drivers are the main reasons, and that's what we should be banging on about.