I have previously made a thread about how the late game air vs air deathball will lead to the race with better air deathball wins.
Traditionally, Terran needs more siege tanks to make sure they can fend off the infestors and queens getting too close. But Thorzain relied less tanks because:
Widow mines can deal air and ground splash.
If the zerg ever tries to do a big engagement, the widow mines, HSM, PDDs, yamato etc will demolish any zerg anti air composition
I can forsee this being the case for TvP air deathball battle as well.