The D5's low ISO dynamic range is obviously a trade-off for it's ability to maintain good dynamic range at very high ISOs. It's one of the very best on the market in that respect. Don't like it, don't buy it.
As far as the D7500 is concerned, don't take Dx0marks scores for gospel. The larger pixel pitch of the D7500 gives it much better dynamic range from ISO 400 onwards than the SAMSUNG.
Dx0mark's maths is massively biased towards high res sensors. And doesn't take into account DR at high ISOs. The sports score is also effectively meaningless as a result
What's the difference between