Collective Might is a fairly average deck. To me, there's not much that really excites me or sets it apart from some of the other decks we have. CM is sorta a mix between a mid-range aggro deck, and a token spamming deck, and pretty much any build is going to have a mix of both to some degree, since you can't really escape all the token cards. I feel this build is a somewhat equal balance between the two themes. With a lack of removal spells and card draw, control really isn't an option here, except for maybe an aggro-control adaptive strategy you may be able to employ against certain matchups.
Creatures - 24
2 Jade Mage
2 Knotvine Paladin
2 Qasali Pridemage
3 Selesnya Evangel
3 Selesnya Guildmage
2 Dauntless Escort
2 Hero of Bladehold
3 Loxodon Hierarch
2 Wilt-Leaf Liege
2 Ant Queen
1 Tolsimir Wolfblood
Other Spells - 14
2 Swords to Plowshares
1 Eladamri's Call
2 Fists of Ironwood
2 Sigil Blessing
2 Beastmaster Ascension
2 Midnight Haunting
1 Marshal's Anthem
2 Parallel Lives
Lands - 22
2 Evolving Wilds
9 Forest
11 Plains
General Strategy: The mana curve may seem odd with lots of 2 mana creatures, but it works here. Selesnya Evangel is great to play on turn 2, follow up with another 2 drop, then use the Evangel's ability to make a token. The Liege and Hero of Bladehold are the 2 main workhorses of the deck, and what you'll be fetching most often with Eladamri's Call. Lots of your creatures are both green and white, so they'll get a +2/+2 boost from the Liege. When you have a guildmage and a Hierarch out there, that boost will let you swing for a lot. Boosting tokens also turns out to be a good strategy. This is an aggro deck, but you want to play it with some planning to your attacks.
Knotvine Paladin - I really enjoy this card. This is another primier turn 2 play, especially if you can follow it up with a Pridemage or Fists of Ironwood on turn 3, letting you swing for 4 and possibly with trample.
Qasali Pridemage - another solid 2/2 beater that gets the full benefit of the Liege's boosts. It's also the only way this deck has to deal with artifacts/enchantments.
Selesnya Guildmage - it's abilities are expensive, but they have both been relevant. At worst, it's another solid 2/2 beater that turn to a 4/4 with the Liege, and the guildmage will likely attract some removal, which is less removal for your bigger and better creatures.
Dauntless Escort/Loxodon Hierarch - good beaters for their cost, they are both colors, and have abilites that can protect your other creatures for a turn.
Civic Wayfinder - He's a bit underwhelming. 3 mana for a 2/2 isn't impressive, and this deck doesn't need a lot of mana seeing as the mana curve tops out at 6 and I've almost never had mana issues with this deck.
Scion of the Wild - I didn't like this card when it was called Crusader of Odric and was in Peacekeepers, and I still don't care for it here. But at least here, it can be a little less of a win more card and more of a stallbreaker since you can give it trample with Fists of Ironwood. However, comboing with 1 other card in the deck is not enough for me to want to run this. It's still a decent card, when you already have a large army and in which case, you're probably winning anyways.
Trophy Hunter - It's not bad as an anti-flyer. The downside is that it costs a lot of mana to take out bigger flyers.
Silklash Spider - This alsmost made the cut. 7 toughness is a lot, and it has a nice anti-flyer ability. If you want an anti-flyer for this deck, here's you guy. The reason I'm not playing him is that while it may be a good defense against flyers, and a good blocker in general, it doesn't do much for you offense.
Nemata, Grove Guardian - It's bassically a bigger Jade Mage. You can run it if you want more token production.
Phytohydra - This is kind of a strange card, but not too useful against a good player. It can be a defensive wall, and while this deck can spend a little time on the defensive, it can't afford to spend too long on the defensive. Or this card could just attack each turn as a creature that goes unblocked, which isn't very impressive for a 5 mana 1/1.
Tolsimir Wolfblood - The pumping from the Lieges are good, and this essentially functions as a third liege for 6 mana. Pumping your creatures wins games, and if you get this and a Liege out, things will get crazy. The token can be nice, but it does conflict a little with the Parallel Lives.
Novablast Wurm - Ok, so this deck does have a form of mass removal, but as a general rule, I don't like running 7+ mana cards in a deck without card draw or mana acceleration.
Sprout - Yeah, this deck likes tokens, but sprout is always underwhelming.
Parallel Lives - When building this deck, I wanted to minimize cards that didn't impact the board or benefit me immediately. It is still a good option to run some of these types of cards, but you don't want too many or else you risk getting stuck with having a bunch of non-impactful cards and you're waiting for a creature or token maker. It can sometimes be hard to find a good time to drop this on the field, especially if your hand doesn't consist of any token makers and you're pressing the offense with Hierarchs and Escorts. There are 16 token makers in this deck (not counting the Tolismirs that don't work with it), so there shouldn't be much of a problem on that front. Parallel Lives is especially nasty to play on turn 5 after playing a Hero of Bladehold on turn 4.
Overrun - I don't care much for overrun here. It's not a bad card by any means, but this is one of those cards that doesn't do anything on its own, and it won't help you come back from a losing situation. The triple green casting cost can be problematic, but I seem to have more issues consistently having a decent sized army by turn 5-6 when I have the mana to cast this.
Sigil Blessing - This is my overrun. For the cheap cost of 2 mana, one of your creatures get's +3/+3, while the rest of your army also gets boosted. It's instant speed, so you can use it as a nasty combat trick on the offense or defense.
Behemoth Sledge - It takes a total of 6 mana to get your first use out of it, and for +2/+2, lifelink, and trample, it's not really worth it. Fists of Ironwood already grants trample, and creating a bunch of tokens can get around standstills.
Intangible Virtue - There's 2 reasons I picked Beastmaster Ascension over this. First, the boost is small, and will frequently leave you wanting more. Second, it only boosts tokens, whereas Ascension boosts all your creatures. On the positive side, the boost is immediate, and it has some nice synergy with the Knotvine Paladins as well. However, in an effort to minimize the cards that don't do anything on their own, it came down to cutting this or the Ascensions.
Beastmaster's Ascension - This is another dangerous enchantment. It may take a bit to build up, but when it does, suddenly your Midnight Hauntings are putting 2 6/6s into play. Another positive is that you can build it up in large chunks. If you have 3 counters on it, attacking with 4 will activate it, and you get the boost on the current attack. Like Parallel Lives, it can be challenging to find a time to play it considering it doesn't have an immediate effect. Compared with Inangible Virtue, it does provide boosts to all your creatures.
Pollenbright Wings - I didn't like 6 mana auras in Pack Instinct or Celestial Light, and those at least boosted the creature's power/toughness.