Justifying looting
The enormous wealth that literally was beneath Alexander's feet was not the result of a single generation but the relentless toil of multiple consecutive ones.
And the enormous wealth that literally was beneath Alexander's feet was not the property of one single individual or an organization or even a family, but the entire savings of multiple generations of the people of Adhan, from the poorest peasants to the richest merchants to the highest nobles.
Alexander estimated the total to be several billion roplas, or several tens of billion tustas!
A sky-shattering amount by any stretch of the imagination
And now it was all his!
Well, at least he wished it was, as Alexander lampooned at his own powerless at being offered quite possibly the greatest known collection of wealth in the current known world but being unable to eat it.