[@Mega Birb] That's a good question. Ellis has his small schooner, but it's three man vessel at best, and Ellis is the size of three men. I'm pretty sure one of the Quarians has their own ship too, as well as Sicaria, I believe.

Who knows, this could end up with everyone bringing their own ships and just forming some oddball convoy.

Oh, and [@Rithy], Cerbs are always a death cult. They're crazy science freaks who are really, really racist. They're the KKK times One million. If you imagine the cops busting into a KKK weapons stronghold, it'd be very similar to to our group knocking on the door of a Cerberus Research and Development facility. Same zealotry, same ideals, same level of hate. They'd open fire on our group as soon as they noticed a non-human. To be honest, at this point, it might be wise to use our three humans to infiltrate and breach. With three humans, Anderson could keep an eye on Ellis, Salissa is there to provide good backup, and suppressive capability. And then you've got Ellis' talents, allowing you to create a large enough diversion that a Krogan in the base is the least of their worries.

That having been said, seriously, Ellis is not trustworthy. Not that he's a common traitor, but motives get skewed in his head. You gotta watch that guy. 

Another cool idea would be to use the advance team as a diversion. If the advance team creates enough of a widespread chaos, the sneak team could get in easy. Right behind them, in fact. But the advance team would need to really make a huge scene. Something like... everything on fire would achieve that.