If the reference is to the various derivatives of lc0, they cannot be counted as different engines.
The links explain why something that is a PART of a GPL program is considered derivative work (regardless of how it is connected or who the author is).
The copyright covers the result of human creativity.
In the case of a chess engine software that result is how the engines plays.
In the case of lc0 how it plays depend on many PARTS: the NN, the implementation of the MCTS search, of the multi-threading, how optimized is the code, ...
Modifying, replacing or adding a part (search's implementation, NN, etc...) must also be released under the GPL.
The viral nature of the GPL is well known and that reasoning cannot be dismissed without producing valid arguments (as you have already done twice).
It might be worth pointing out that the copyright is not related to the physical format. I can write an article in Word, convert it in PDF or print it on paper: still the same copyright.
However the thesis that a neural network is like a mathematical formula and cannot be copyrighted is also worth consideration.
I repeat: it is complex and I do not want to enter into endless polemics.
The point and the reason why I replayed to the previous post is that no one can say: shut up, I am obviously right and you are wrong.