Well the thing is, I don't have the problem in my setup because if I have a translatable productpage with products, I don't create any relationship between my productpage and my products anyway, because I only have one productpage. So I just create a method on the productpage to get all my products, that you would need to create anyway to allow sorting, filters, pagination ...
I don't think the decorator can help with this, because it's an inherent problem with translatable. See this link for more info for instance
http://www.balbuss.com/translatable-duplicate-linked-dataobjects/