I think you should ask that on the hints thread. But it goes something like this:
No, you don’t need 2 INT. What you do need is the correct info, and you can coerce Bleys, tap into the merchant network or get a fellow noble (Aristo MC only) to tell you where the Architelone is going to pass.
But I only know how to do the Bleys route: you need to threaten his family, and to do that, you need at least 1 INT, after that you should pick the choice where Ciels threatens his wife, knife in hand. And, if you send the tax Architelone after Alaine or Ismene, you’ll be able to convince the Telone to join your rebellion.