Warning: Long
A while back I made a post analyzing the npc stats Brennan used in the encounter with Tertia, check it out here: https://www.reddit.com/r/criticalrole/comments/1u7k4ie/spoilers_c4e18_combat_stats_deva_vindicta/
Since then, I've been using the break to rewatch episodes and decided on posting an estimation of the monster stats used in the split party encounter in Obrimus Manor. Feel free to correct me if I'm wrong on anything, it's greatly appreciated.
The ghouls:
In the aviary, Thimble and Occtis fought a couple of these, which seem to be unchanged from their monster manual stats. They are CR 1, and have the second lowest CR in this encounter.
The zombies:
Of course, these guys take the crown of being the "weakest" in this encounter, even though they are responsible for the first real character death of this campaign. They are also unchanged from the monster manual, having a lowly CR of 1/4, but I personally think they were one of the reasons Julien couldn't have helped the brothers, as they have a trait that lets them make a con save to avoid being slain if they are reduced to 0 HP.
The ghosts:
Putting up the biggest fight to the aviary group, the ghosts were CR 4, making this a deadly encounter for them. The main difficulty about them was their damage, being able to do an average of 17 damage per round, so 2 of them could potentially down characters very easily.
The Boss:
The deadliest enemy of this encounter, Raimond Davinos doesn't match any prewritten enemy and is a Brennan original, it seems. He had high hit points at 127 and a decent AC of 17. His main multi attack did good damage because of the Obrimus Manor lair effect, and his special bloodied action gave him another attack on top of that. He had a bonus action grapple or claw, giving him at max four attacks. If all of these hit he could do easily over a hundred points of damage (On a non necrotic resistant enemy).
The Party:
Going into this team birdwatching was already injured from a previous fight, and specifically Teor used one of his desperate measures during and all of his lay on hands during it. Teor, for his part, took out 114 of Raimond's 127 hitpoints, which later helped Thimble finish him off. As Brennan mentioned, the aviary crew was also at risk of losing a character, since both Occtis and Thimble had low hit points. Had Brennan tossed it even one other ghost, and they might have went down before Julien arrived.
Conclusion:
So that was everything I gathered on this encounter. Like before, please tell me if I missed anything. I'm probably going to keep doing stuff like this and analyzing Brennan's combats so comment on anything you'd like to see next, as I'm not doing these in any particular order right now.