Hill, Sondland, Morrison, Taylor, Holmes, Kent, Vindman. These people didn't get together, cook up this policy on their own. They instituted the policy they were given. The policy is a fact.That's not hearsay, that's not opinion. Some, mostly Sondman, gave their opinion of why there was a such a policy when asked.....but the career diplomats didn't go there.
The policy got to them from trump through Rudy. Besides possibly Pompeo and Mulvaney, it's unlikely anyone else got any marching orders directly from Trump.
Just like the mob, the top guy is insulated. Rudy can't be forced to reveal attorney client conversation, trump is blocking Pompeo and Mulvaney and anybody else he talked to from testifying, there's no one left with direct knowledge. But people are convicted every day without "facts". Juries can draw their own conclusions. In this case, the conclusions are obvious. The questions surround the jury.
I know that all probably means nothing, just go back to your process arguments.