The problem is that the Runner fleet is already acting highly irrational.
If we truly were Aquilans, we would never have come aboard the ship.
If Tai'lon truly was an Inquisitor, he would have gladly sacrificed the captured auxilary crew for sending out a message.
On top of that we have to considered that the Runner fleet is operating on essentially zero knowledge about the Aquilans.
They first is they were our first bussard ram equipped FTL rockets, with a theoretical range in average density space of almost four hundred light years without stopping to take on remass, and at remarkably low radiation signature. The second is that they were equipped with passive cryogenic suspension systems, based on the ones used on Aquillian mining stations, which would allow the crew to enter suspended animation for as long as three decades if needed.
The Scorpions were build very early in the war, given that they are the first bussard ram equiped FTL rockets, so I think they predate even the Liberty rockets.
What information they had at the time was what they could salvage from the fleet that attacked Sol, and maybe some nearby platforms they overran.
The Runners meanwhile know nothing more than what they could glean from random broadcasts.
Given that with a bit over 20 years distance, the guy can no longer recognize human civilization, I don't think we should count on him not believing that the Aquilans have changed in 900 years.
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Anyway, the problem is that the Runner Fleet is already teetering on the point of a conspiracy. They fear the Aquilans, and I'm not sure that an approach which plays into their expectations of the conspiracy (namely, transmitting a bunch of propaganda) will help, even if logically it should. Because what's happening here is fear, combined with what I suspect with an inability from the human personnel to accept the truth. Note how it is the human commanders onboard the Scorpion who are the ones proposing that we're an elaborate fraud, while it's the Runners who're advocating patience and different options.
So, we need a response to that fear, beyond just mere logic.