I agree with GameGraphix on the whole loosing potential D’Orcs issue.
how Orcus solved that problem should be included.
i can think of two ways.
a soul pool where any mortal souls orcus was linked to go when they die.
or Orcus prelinking them if they were promising orcs so they would go staight to the abyss to get revived.
that Orc that fought in ragnarok was the one that said he got killed in that fight.
If Orcus did not have a second way of creating Orcs.
he should’t exist.
About the mana pool i think by the time they go to the isle of doom it just started to generate excess mana recently. so the amount of excess mana they have is too low.
most of it is currently keeping the Doomplex running excess going to powering up the doomalogues.
which may be the reason they had to use the ritual.
no excess mana to just sap the D’Orc to be.