Have you thought about Banisher Priest or Fiend Hunter

I've considered them (and was rocking Fiend Hunter 4-5 years ago with my very first attempt to play modern), but overall they have several innate disadvantages to them here. While they are essentially a removal spell tacked onto a human, if they are removed it doesn't help much and will trigger ETBs of creatures removed with them. This means that it is usually in poor taste to target creatures with ETBs with them, and on top of this, it allows your opponent to "flash" in a blocker at instant speed by removing them at instant speed. I'm also looking to keep the curve low, because I have a surprising amount to do on each of my turns and I'm fairly happy with where my curve is currently at. Fiend Hunter and Banisher Priest are good cards, but I don't believe that they have a place in this particular build. Thanks for the suggestion nonetheless!

If you're going to be playing green, You should definitely be playing Collected Company

Many suggest Collected Company, but it surprisingly doesn't fit the deck as well as one would hope it would without building the deck around it (which this deck doesn't do). Besides a high creature count, I've found that CoCo decks usually require a few other things to be good. They usually require mana dorks like Noble Hierarch and Birds of Paradise for a turn 3 CoCo, they have multiple big flashy cards to play at instant speed, the creatures have even greater effect when flashed in off of CoCo, and they have a prevalence of 3 drops. While not every good CoCo deck will meet this criteria, I believe that all of them meet 3 of the 4. This humans build has a very low curve (meaning low value hits off of CoCo), 2 3-ofs of legendary creatures in Kytheon and Thalia, doesn't have many creatures that feel as impactful at instant speed, and doesn't have other things to do at instant speed as much as other decks might. In addition to this, Thalia interferes with CoCo, and I only have 7-8 green sources to play off of CoCo because of Cavern of Souls. CoCo is a great card and humans can certainly be built to exploit it, but this particular build is leaning in a different direction. Thanks for your input!

So, on CoCo. It's a major recovery spell, to recover your board presence after a wipe or to fight through removal, and I don't see why it doesn't do that here, or how that isn't good here. But, I'll do the math for you. 15 1-drop targets, 14 2-drop targets, 2 3-drop targets. 31 targets in total. You have a 00.85% chance to hit 2 3-drops, a ~13% chance to hit 2 & 3 drop, a 51% chance to hit 2 2-drops or better, and a 91.6% chance to hit 2 creatures. From how your deck plays based on testing with you, I would expect even hitting two 1 drop creatures EOT to be powerful, as effectively a 4 damage 4 mana spell. I understand you dislike the antisynergy with Thalia immensely, but as long as Thalia is on the board, you're doing pretty well, when she's gone, you cast CoCo, and recover.

I mean there is a reason why every competitive modern tribe/Bears deck plays Collected Company or Aether Vial All of them

I'd even go as far as to say drop All Precinct Captain's for 4 Noble Hierarch's and drop 2 Thraben Inspector's and 1 Kytheon, Hero of Akros  ^Flip for 3 Eternal Witness to get back company. -3 Brave the Elements -1 Mana Tithe +4 Collected Company I know you have a vision here, But this keeps you with your tribe and will guaranteed make the deck better.