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.

Goblins don't play CoCo or Aether vial. His curve isn't quite as aggressively costed but its close enough. given his curve I could see not wanting to play CoCo, especially with no mana dorks and with only 3 3 drops. I do think there is enough 2 drops to warrant Aether vial though, or at least extensive testing with it.

mahanhen Goblins is not a seriously competitive deck. Although fun. Not in modern atleast

Very nice build, +1

With only 11 green sources, I could see problems reliably casting Mayor of Avabruck  ^Flip. Have you thought about another Horizon Canopy or some Temple Garden to help? Also, have you tried Boros Elite? Seems meh against removal-heavy decks, but great elsewhere. Also, what has you experience with Mana Tithe been like? Seems meh to me since you don't ever want to be leaving up mana.

I've actually been quite happy with my ability to cast Mayor, I very rarely have problems casting him. Boros Elite is too often a lackluster 1 drop that doesn't activate too often, and when it doesn't activate it is practically dead. Mana Tithe hasn't been too bad honestly. It's a 1 for 1, but I've had decent success with it and can almost always trade with a card througout the game at the very worst. I've looked hard for something I'd replace it with, but I honestly haven't been able to find anything. It fills a few roles in the deck surprisingly well (extra turn 1 play, extra protection, makes my hand harder to read if it was already revealed in the last game or 2). I agree that I rarely want to be leaving up mana, but as with almost any deck, there will likely be room to hold up 1 mana for an instant, and having potentially 3 options instead of 2 has been good.