I thought the swarm command broke single part turrets? 
No, it makes them fire down normals.
Which kinda breaks singlepart laser turrets as they can only fire straight forward, but that's about it.

Think about it, the Moloch spams you with swarm missiles just fine, (albiet not very effectively) and they always fire straight out from the firepoint before homing.
The Apocalypse torpedoes on the Karuna, Narayana (and Solaris?) all have Swarm, as do the Warhammers on the Sanctus.

Swarm definitely does
not break singleparts if what they're firing has any sort of homing.
(don't do it with dumbfire missiles or primaries though or it'll look silly)