Our DNA similarity to a Chimpanzee is 98% for genetic DNA and around 94% for genomic DNA.
Our DNA similarity with a Neanderthal would most likely be 99% for genetic DNA and around 97% or more for genomic DNA.
That is just comparing DNA sequences. It was from ANALYSIS of human DNA segments and comparison with Neanderthal segments that made them estimate that out of 100 great to the nth power grandparent the typical person has, one to four of them was a Neanderthal.
Do you perceive the difference?
If you got a Lion Tiger mix to successfully breed into the Tiger population, a few hundred years later you might estimate based upon DNA that that Tiger population was around 1 to 4% Lion.
That doesn't change the fact that Lions and Tigers are whatever % similar when comparing their genetic DNA.