I know NOTHING about arowana's, but I have had dealing with baby silvers with the yolks still attached...
I wholesale ordered fish with another person and they ordered 100 silver aro babies- when they came in, they still have the yolk sacs. (none of them survived past a month)
But, from my experience, I can tell you that they don't look alike- this is just my opinion.
I think everyone on here was trying to warn you that you are almost indefinitely setting yourself up to lose money with them being so young right now. I don't see why you can't ask the person to hold them a bit longer until they would be less fragile.
No one is giving attitude, and no one is asking for it in return. If you don't want our advice/input then simply don't post on a public forum.