I already worked on the editing/typesetting of this work before... but when the Digital version came out, with a new page, I decided to redo eeeeeeeeeeverything. Thank you Asdier for translating this new page (p32).
They are ejust summoned "heroic spirits". Basically... they aren't the real person... and each time it is summoned it is based on the memories of the hero that died. So the "Saber" that had sex with "what's his name" in the first game, isn't the same Saber we see summoned in other games. Every time you summon saber, that Saber is blank slate. In other words, the Saber that was summoned back then, ceased to exist later. What I am saying is that it isn't "the soul" of Artoria that is being summoned every time... but jsut some memories that is then taken form using spirit energy.
This is also why somebody like "Mysterious heroine X" is so interesting because she must have been born in a reality where there were a lot of summoned "Artoria" from different realities.. perhaps even multiple people even summoned the same "saber" from the same reality. Basically, she was born in a world where people constantly summoned the immenselly popular "Saber", used them as soldiers and then as sex toys.
It isn't odd at all that X wanted to get rid of them all.