These are relevant references from the Books where a Trade Advisor is mentioned.
I make no pronouncements on these matters, but report them as I find them.
Arrive at your own conclusions.
I wish you well,
"My master," she said, "Decius Albus, of Ar, Trade Advisor to the Ubar, welcomes Lord Grendel to the city. He regrets only that he was not earlier informed of his presence. Master Decius understands that Lord Grendel stands high in the estimation of a Lord Arcesilaus, magistrate of a remote city, and hopes that his presence here might lead to arrangements of mutual profit. With this end in view, Master Decius invites the presence of Lord Grendel, or his agent, to a meeting at the tenth Ahn tomorrow in his home, the House of a Hundred Corridors."
"And how, slave, do you understand this?" inquired Kurik.
"I am only a slave," she said.
"Speak," he said.
"I speculate," she said, "given the office of my master, that of trade advisor to the Ubar, that he is interested in the possibility of establishing trade relations between Ar and the city of the Lord Arcesilaus."
"What city is that?" asked Kurik.
"I do not know," she said. "We are told little. We are slaves."
"Perhaps your master is interested in an exchange of valuables," said Kurik.
"One supposes so, Master," she said.
"Tell your master he will be attended upon at the tenth Ahn tomorrow," said Kurik.
"Ho!" cried Decius Albus, jovially, lifting his hand, and separating himself from the group about Kurik. "We have welcomed noble Grendel, of far Mytilene. We have introduced him to colleagues and compatriots, to representatives of diverse castes, herein publicizing his presence and the nature of his charge. His appearance here, as his purpose, is now well accounted for, as the lists will show. An official invitation was authorized and issued; it has been acknowledged, and, obviously, accepted. The records will show this. Now, dear colleagues, and friends, it is time for the subtler aspects of our meeting to begin, in which we must attempt
"The matter," asked a fellow, in the white and gold, "should be mentioned to the Ubar?"
"Of course," said Decius Albus. "We have no secrets from great Marlenus, our beloved Ubar. Naturally he will be kept informed of all proposed arrangements in a suitably prepared memorandum, long before we consider drafting a formal document, one to be submitted for his review, signature, and seal."
"'Decius' is a not uncommon name in the vicinity of Ar and Venna," said Addison Steele.
"I would not know," I said.
"There is, for example, Decius Albus, the trade advisor to the Ubar of Ar, Marlenus," said Addison Steele.
"Stand back," he said. "It is a personage of preeminent importance, the noble Decius Albus, trade advisor to the Ubar."