The court heard Vector was also seeking to have its prosecution continue solely against the suppressed company.
Ross described it as "a tussle over a corpse, if I can put it bluntly".
He argued his clients having a contradictor in the courtroom, similar to an amicus curiae, would ensure the company had a fair trial.
Vector's lead counsel, David Jones QC, said the issue of the parties' standing in a criminal case needed to be determined first.
"We have legally represented defendants," he told the court. "What [the parties] are trying to do is say 'we don't like the way you people are dealing with this case and we want to put our oar in'."
He argued the parties wanted input "for their own interests" and were "casting aspersions on Vector's motivations".
Jones said the lines company had commenced the criminal proceeding as a "matter of principle" and wasn't seeking reparations.
But Ross said Vector has a "very significant stake" in the outcome of the proceeding.
He also accused Vector of "hostage taking" if its desire was to prosecute the suppressed company alone.
"They are saying to the court and to [the charged individuals], 'we'll let you go but only if we get a conviction against the company'," Ross said.
Justice Jagose asked: "Stockholm syndrome? Is that what you're saying?"
Ross said yes and nodded in agreement.
Counsel for the company's liquidators was also opposed to a contradictor being appointed.
The judge reserved his decision but indicated to counsel it could be "expected reasonably promptly".
About 18 charges were first filed against the defendants in February 2017 in the Auckland District Court.
The NZX-listed Vector has previously issued public statements about what it has called a $1 million fraud during a "significant project".
"This followed a whistle-blower from the company raising serious concerns with Vector," the company said in 2019.
"Vector has taken this action because it strongly believes that if this type of illicit conduct is left unchecked it leads to inflated infrastructure costs which in turn flow through to electricity prices for Auckland energy consumers, who are Vector's majority beneficial owners.
"It is in the public interest for fraudulent behaviour, wherever it occurs, to be called out particularly given its substantial negative economic implications."
A trial was due to be held in October last year but is now set to be heard in February 2022.