Two, they gather up forty-thousand people or something absurd like that, or thirty-thousand frankly would be more than enough to make a direct confrontation unwise, and then... we'd have to retreat back to the other bank. We have scouts, I don't think it'd take multiple days (and we'd at least get a day or two info in advance) for us to cross the river without the enemy bearing down on us.
We don't have a force able to attack a provincial army like Trotha's, which is why we resorted to defense. I think the chance of them sending a force we can beat without a good defensive advantage are next to zero, leading to a likely scenario where we cross a river, ignore direct orders, only to retreat across the river again.
My other problem is that, by the time we're at the South Bank of the river, we'll be, like, a week and a half from communication with them. Each way. So this would imply that we're waiting at least three weeks and more probably months or "literally never" for orders from a Convention that's kinda busy. Like, the further north we advance, the more waiting for every single order becomes unwise.
The assembly was pretty clear in setting limits for our operations. This isn't a case of us waiting for orders, this is a case of them telling us what to do "Don't go over the Raoille and defend", rather than letting us operate how we see fit. Now, I think the spirit of their order was "Don't undertake offensive operations", not "literally don't put a single boot north of the river", but they were clear in setting us an operational area we have to stay in. Worrying about this act of insubordination being used by political enemies against us is a valid concern in my opinion, and I would generally prefer to stick to their orders if we don't have a very compelling reason not to do so.
I also don't know how you arrive at the 3 weeks for communication. The last time we sent a letter to them requesting updated commands we were at Martelnac, just before we took Daurstein (Sub-Turn La Durance: Terms of Surrender) our timeline was something on the order of a week.
The Fifth Army advances. While the bulk of your force moves north, messengers ride back along the northern road with hastily-written letters from you. One is to Guillory, calling on him to join you at Daurstein posthaste. The other is to the Convention, explaining the situation and your actions.
We heard back from the assembly a week later, since we communicate with them via a fast system of couriers. We received our response a week later (La Durance- Third March results), where a lot of the time presumably also involved debate rather than the pure delivery of the letter.
On the 22nd, you receive word that Guillory has arrived in Grigny-sur-Vaud with the VI. Army. That should put him at Daurstein on the 24th. He sends a messenger before him, with an enlightening letter:
I don't see us taking much longer than that to communicate when we move north. We are talking about a single messanger moving with a horse, and handing the message over to the next one. 3 weeks for communication by moving a few days north is unlikely.