You may believe whatever you like about when a human being actually becomes a human being, and may define those words as you choose. As for this issue being a scientific one, it is not. A definition of humaness is philosophical, not scientific. There is no way the definition of "human being" can be axiomatic.
No one denies that a new life begins at conception. This is the red herring always thrown into this discussion. Every cell is alive, but being 'human' requires something more than just being alive.
I am going to suggest a solution. When I refer to a human being, I mean a "living breathing" human being. When you refer to a human being, you mean anything that might eventually become a "living breathing" human being as well as a "living breathing" human being.
This reduces our disagreement to a matter of definition. I do not deny that a fertilized egg is alive, or that an embryo or fetus are alive. I do not deny that, barring any problem or difficulty, these will become "living breathing" human beings.
If we accept your definition of human being, a new word will be required for "living breathing" human beings. If we accept my definition, a new word will be required for your idea that whatever will be or is a "living breathing" human being is already a human being. Or we could adopt the current usage of zygote, embryo, and fetus for what is not yet a "living breathing" human being but probably will be, and "human" for what is actually a living breathing human being. I leave the choice up to you.
I have always considered myself marginalized. The truth is hated by most. I have no interest in convincing anyone else. I have answered such questions as others seemed interested in asking. If others do not choose to think for themselves, it is their choice. I have learned, being right always puts you in the minority and the more right you are, the smaller the minority. Knowing the truth does not require anyone else's agreement.
As for the "the learned offering in the above article," it was so much pompous pseudo-scientific blather, but some are impressed by such things. I do not mean such science as was discussed was incorrect, but that the philosophical conclusions drawn were spurious. Evidently this seems quite "credible" to some. Personally, I have no desire to be credible. I do not want anyone to believe anything based on what I say. I want people to use their own best reason to honestly examine what they believe and allow no contradictions.