Cubs do an insane amount of work, but swarms as a whole I think are gone about in generally the wrong way. My reasoning for this is through playing with swarms quite a bit, and seeing the different strategies my opponents will use to counteract it. I think swarm builds tend to be incredibly aggressive. They send all of their time building a creature presence on the board, that when that is countered, and sometimes, like with Gravkor against falcon punches, that creates the writing on the wall right there. Rather, the way I've started building my swarm books is to use the swarm as more of a building block, and an hourglass. If I am forcing them to deal with my little creatures, it's giving me the time to build a stronger board presence. In this way, when my swarm is ultimately decimated, I have the board presence to continue my game. I've also been playing with a Lair swarm strategy with straywood, in which you get to a point early on where you spam 3 hawks for two rounds. In this way, the opponent thinks once lair plus x drops that you are going for more of a buddy build. Bringing up a swarm quickly forces them to interact with those creatures, and even if it's a short amount of time, it's the time you need as a player to build up board presence that would otherwise be considered gote threats. Something like:
19
Lair -15
Ring of beasts -2
2
11
Mana Flower -5
enchant ring-2
4
14
Hawk from lair -3
hawk hawk -11
10
harm on lair -6
move twice
14
Hawk from lair
hawk hawk
this is just a basic idea of course, but alternating between spending time one board presence and spending time spamming divides your strategy in a way that forces the opponent to deal with one or the other.
The other way I have thought about swarms is to Swarm now, Lair later.
19
Ring of Beasts -2
Mana Flower -5
12
22
Hawk-5
Timberwolf-9
8
18
Hawk-5
timberwolf-9
4
14
Enchant ring-2
Move twice
12
22
Lair-15
Harm on lair-4
3
13
This method shifts the momentum of Lair from something you depend on because you spent all of the early moments investing in it to a strong support spawnpoint that has time to build up because of the previous creature presence. This, of course means that the build is not hyper aggressive at all, but that isn't necessarily a bad thing.
These are just a few of my thoughts on the matter, and I would be happy to hear what you all have to think about this whole thing.