And because they claim it's both large and very general, they need to present evidence to support both these ideas. To me the claims in the paper do not really

And because they claim it's both large and very general, they need to present evidence to support both these ideas. To me the claims in the paper do not really seem that strong, almost to the point that I am not sure if they claim anything at all. If you read through the conclusions, they mostly report the findings of their experiments. The closest thing to any claims about generality I can find is that they discuss in which scenarios their findings will not apply. You could maybe read into this that they claim that in all other scenarios their findings apply, but that is not what they actually do. But I guess the better way to discuss this is that you just quote the claims from the paper that you consider too strong and unjustified instead of me trying to anticipate what you are referring to or me going over each claim in the paper.