As I see it Swarm has 3 central playstyles.
Satyr Hordes, en masse, cheap and unrelenting. (I'm doing OK here, but my Restless Goats are level 3, which is almost the bar for functionality)
Undead Chip inevitability, with Vindicators and Pillar of Doom and Mischiefs (this can be harder than it seems if it is your only playstyle)
&
Most Swarm decks focus on the last [Herald's-bloody-Hymn, get used to it, they won't take it out of the game] in particular, with hints of the other two to varying degrees.
And it works like a hot damn, obviously; as evidenced by the 14 hp players in Diamond 1.
I have a personal distaste for decks which lack some form of thematic cohesion. They just don't do it for me.
"As many inexpensive units as possible" or "Constant flood of two-movement units" does not, to me, constitute a theme.
I'm not saying they don't work, I simply don't like them. Without thematic cohesion. (Pirates have two, very strong, two movement units. Dwarves have five)
Swarm and Ironclad have numerous inexpensive units - including Neutral units - which share type & have Synergy between those units (Constructs & Satyrs - Upgrade Point, Swarmcallers, etc.) which push them, generally towards a flood of smaller units, then delivering the payload.
Let's be real, though, the game is seldom won through attrition; it is often ended in two or 3 blows. I think a lot of us enjoy the gameplay and the tactics that emerges from trying to break the opponent's line and flood their base (and fighting back from that)
The game of ignore all distractions in a race across the line diminishes that exchange, somewhat.