I know there are all sorts of camps in the Panttore/Dottolone ship right now, ranging from "Pantalone only liked the original and disdained the Segments for what they did to Zandik" to "Pantalone was married to all the adult Segments and viewed them as individuals" I am not above Pantalone harem propaganda, but in terms of the comments he made in the game, I've been mulling over my personal interpretation, and I think Pantalone had a very different understanding of the Segments than many fans seem to:
Pantalone insists several times throughout his scenes that the Segments are Zandik. Not copies, not dolls with their own existence like Wanderer. Actually Zandik. While a lot of the fandom currently treats the Segments as basic clones, it seems (to me at least) that Pantalone interprets the Segments as shards of a greater whole (the word in Chinese used for the Segments can be translated to "sliver" as well).
That is: One day Pantalone woke up and had to face the reality that the man he'd worked with and relied on for decades, his only friend, had successfully dissected himself into seven pieces, each with 1/7th of the original human soul. It appears likely to me that, in Pantalone's eyes at least, Dottore never "made clones"--he simply threw the fragile vessel called his existence at the wall and then named the broken slivers an ingenious creation.
Pantalone never had "Zandik" and "six copies of Zandik."
Having seven shards of one broken mirror is not the same thing as buying six copies of the same mirror.
Even if they all stood in right front of him in seven different bodies, there was still only one Zandik in Pantalone's eyes.
From the moment the Segments were created, Pantalone only ever had the scalpel-thin slices of Zandik left, all of which needed special handling to keep from crumbling further. 8 wasn't just a random doll running around--that was literally Zandik's childhood made manifest. 35 wasn't just a useful clone for keeping the "Dottore" role alive--that was the darkest piece of Zandik's soul, the peak of his pride and cruel ambition, given flesh and blood to wreck havoc with.
Even the OG Zandik, despite keeping all his memories, would no longer have had the soul; whole portions of his Self were instead excised like harvested organs put out on public display. (Nahida's comment that the Segments were an "affront to life" won't leave my mind.)
What would it be like to look at the person you love and just see pieces?
And this, to me, is partly why Pantalone was truly unsettled at the original Zandik's death. Pantalone didn't lose his "real" friend and get left with "fake" replacements. He lost part of the whole. Until the moment of OG Zandik's death, all the broken pieces were still present. What was sliced up in parts could still have been made complete one day, like holding on religiously to the shards of a broken teacup that you loved beyond measure. So long as all the pieces are still present, you reassure yourself that it can still put it back together again in the end.
But then a crucial piece was gone. An entire shard missing.
Once even one version of Dottore died, it became harsh and unforgiving reality: The segmented thing Zandik had become would never be a whole person again.
And after that, it was easier and easier to lose the scattered slivers, leaving only a single shard--then Pantalone had to watch that piece break itself even further and willingly leap into death's hold.
I know people say that Pantalone is the exception to Wanderer's comment:
Is grief not among the cruelest suffering of all?