You've already seen two pieces of corroborating evidence that exactly that was considered, Walt. One is from Lamon, who states himself to have been tasked with that job. The other is from Brown, who participated in a conversation with Taney about the dangers that both were facing with regard to arrest. In addition I've read biographic reports of Taney that state he informed people around him of the anticipation for his arrest at the time of Merryman. A nineteenth century biography of Justice Curtis also recounts that a crime was almost committed against Taney by the administration over Merryman - an obvious reference to his planned arrest.
The evidence of a plot to arrest Taney is in the very least corroborated by more than one source. You do not like that fact though so you attack those sources and even deny their existence. But nothing more is to be expected from an intellectual lightweight and habitual liar like you, Walt.
You've already seen two pieces of corroborating evidence that exactly that was considered, Walt.
I've seen hearsay and I've seen Ward Hill Lamon's account compromised by the fact that it is not corroborated.
President Lincoln had no reason to arrest Taney.
But just being the Chief Justice doesn't mean he couldn't commit treason.
Walt