170,000 is three orders of magnitude less than the number of recorded protein sequences. I don't think it's dismissive to describe that as comparatively few.
Structure is much, much more conserved than sequence. In other words, protein sequences with low sequence identity can fold similarly due to the physical constraints that guide protein folding.
I also don't know the field and the opposite concern is that 170,000 sounds like a lot, but, apparently, it's a relatively small amount compared to the number of proteins there are. It makes sense to me to refer to it as a small number - e.g. "That hard drive is tiny." "No, it stores several million bytes..."
