What I find interesting, is that WT and GA often write that species A is related to species B or that A and B belong to the same branch or group
I know what you mean. In line with what OTWO said, the Insight book under the heading, "Ark" states:
"It has been estimated by some that the hundreds of thousands of species of animals today could be reduced to a comparatively few family kinds; the horse kind and the cow kind, to mention but two. The breeding boundaries according to kind established by Jehovah were not and could not be crossed. With this in mind some investigators have said that, had there been as few as 43 kinds of mammals, 74 of birds, and 10 of reptiles in the ark, they could have produced the variety of species known today."
Since Noah couldn't possibly have collected samples of every animal species (There are over 25 species of Jaguar just to take one example) it's claimed that the Biblical term, "kind" must refer to a higher taxonomic group than species, like genus or maybe even family. That would mean vastly fewer animals would have needed to be collected.
But this amounts to a frank admission that large groups of species did in fact descend from a common anscestor and therefore are gentically related. To borrow the terminology from the Insight book, the "Cat kind" would include the Ocelot, Leopard, Mountain Lion, Jaguar, Margay, Serval, Jaguarundi, Carcal, Bobcat, Lynx, Lion, Tiger, and Cheetah just to name a few. And if you include the smaller cats as well, there are many more members of the Cat family even than that.
Like you observed, you're not very far at all from evolution at this point.
Another problem with this idea is that the Bible uses the term, "Kind" very much in the context of reproduction. But with large and diverse animal families, the individual species are not all fertile together. Fertility gradually tapers off as individual species become more and more disimilar. Genetic incompatibility begins to manifest itself in sterility of the offspring and progresses to the point where sperm and egg will not combine to form a viable zygote.
Most "Dog" species have 78 chromosomes. But the Maned Wolf only has 76, the Grey Fox only has 66, the Fennec Fox 64, the Bengal Fox 60, the Racoon dog 56, the Kit Fox 50 and the Red Fox 34. If we speculate that all members of the Dog family descended from a common ancestor than this family has diverged into new "Kinds" even by the Biblical usage of the term.