@Gorlom:
It should be obvious how i define death: when the original spirit leaves this world unable to return to a body. which means that all the zombies were already dead even when they were reanimated, making it impossible for them to die again.
But that´s exactly the point with the zombies. They are completely new beings based characteristics from the shadow owner and the body. Zombie Ryuma is not the original Samurai Ryuma. Samurai Ryuma is dead, his soul long gone. The only thing that remains of him in Zombie Ryuma is the reflexes and strenght of the body. And Brooks character might influence Zombie Ryuma´s personality he remains being an own entity. It´s somehow similar like with family relations on the field of characteristics. Some siblings sometimes have personalities like twins and yet on some field they are different again.
Same goes for the Oda-verse zombies. They may be walking in dead bodies, but they got living personalities none the less. Which makes them living characters. When I say that a zombie dies, then I´m not talking about his body but about his personality. The fact that Laura couldn´t really remember Nami shows that this personality doesn´t exist like that before. Only a fragment was left that made her say "Namizoh" but other than that, the character who wanted to kill Nami and saved her later on doesn´t exists anymore, meaning she´s dead.
Theoretically Moria could steal Lolas shadow again and reanimate the warthog. SO imo the zombie Lola isn't really dead (assuming you considered her reanimated state being alive), merely confined to a souless state indefinetly.
I´m not so sure that Moria´s powers work like this that in such a case we would speak of a continuation of the same existance. We´ve seen that Moria first makes a bond with the shadow where he says that he´s the master before the shadow gets inserted into the body. And with what we learned of the salt that bond gets severed. That´s also why Moria could just control the zombie shadows for Shadows Asgard and not the shadows of Nami, Usopp, Sanji and Usopp too. So in other words, once the bond is severed and the shadow is back Moria doesn´t have any control over it or otherwise Brooks shadow would have been used for Shadows Asgard too.
So this means, that if he would again take a shadow from the same person, he would have to form a new bond because the old one doesn´t apply anymore, which in the consequence means that the shadow doesn´t remember anything from before and we start at zero again. So if Brooks shadow would again find it´s way to Ryuma´s dead body it is very likely that he would develop the same way like before. But it would be a totally different character because the personality of the previous Zombie Ryuma is already dead.
I'v seen a bit too many fictional works containing body switching to consider a body losing its original soul to be a death.
But everyone is free to define death in their own way.
Well yeah, that´s the point. In a fictional world with fantastic creatures the borders are definitely wider to when including something as alive. Technically none of the humans in such works are alive. They live only as characters in the fictional work respectively in our imagination. From that point of view Jigoroh is as much a living character as Monkey D. Luffy. Meaning that his annihilation counts as dead in the fictional work for me.^^