I think someone suggested this before, but we have lots of newcomers, so lets get lots of input.
Ahlverez thought the ICA only had 200,000 men when he's wondering what DE is up last November [LaMA; November, chapter 4] with large garrisons in Tarot, Zebediah, and Corisande, so that sending 45,000 men was the maximum remainder he thought they could send to effectively rescue DE, by threatening the AoS's supply line.
Magwair back in September [chapter 4] now had proof that Clyntahn had lied to them, but no further details were provided.
Generally this has been thought to refer to his semi-secret messages to Kaitswyrth, but suppose they were copies of what the various army CO's had been briefed regarding the enemy, all provided by the inquisition at ZC's direct order, which was far less than what the Go4 knows the ICA to be?
He may argue he did it to encourage the soldiers of god to smite the heretics etc, but proof that he'd lied and thus had helped defeat god's armies, and was now subject to the 'punishment' might rattle him enough into ordering Rhobair's execution.
Since Rhobair might easily be the most popular vicar in Zion, thanks to major Phandys that attempt could easily backfire, causing the common people of Zion to rise up against Clyntahn and the grossly outnumbered inquisitors.
When this might happen would be very interesting, does Allyn hold this back or let Rhobair know, so he can prove it independently?
How's that for a RFC delivered curve ball?

What is Rayno's fallback position?
Does he join the rest of the Go3 in arresting the grand inquisitor?
The assumptions that argued he could never rise any higher have drastically changed in light of the recent turmoil, so the Go3 might easily be very willing to support him replacing his ex-boss if he can do it.
Ah, interesting times...
L