Even two of the same year may not be able to be classed as identical. Particularly with used items condition becomes a unique attribute. There may also be other factors such as mint identification, markings, errors, etc.
You have to use those unique attributes somehow in the title to prevent the robot seeing them as identical.
In an ideal world people would simply abide by eBid's rule and there would be no need for these sometimes clumsy robots that can get it wrong occasionally, or make listing unique items difficult. The sad fact is that there are always those who either simply ignore rules (as they apply to everyone but them) or think themselves very clever in getting around a rule. As so ofen in this world the majority must suffer for the selfish actions of a minority.