I guess I should have clarified this, I don't think zerg would need a solid endgame army if protoss or terran doesn't have one(deathball). Bio terran is a great way to show cast this, both players will make a mix of low and high tier units that will keep fighting until one side eventually loses its ability to reproduce its army, whether its due to lack of resources or destroyed production facility's.
On to the development of zvt.
The standard opening Wol was basically gasless 1 rax expo with a hellion banshee follow up into a marine tank timing, the most common one was probably the 2-2 pre-ultratiming. Maybe 1 out of 10 games was a two factory blueflame hellion all in. Since the hellbat change it been similar with a reaper expand into hellion banshee, armory is optional. The biggest difference is the way medivacs has changed timings, Its become a lot like tvp was in wol, where all the "deadly" timings hit with medivacs(other than a few recent hellbat all ins).
Where as wol timings was largly based on upgrades, this was partially due to the way that tanks don't really allow smaller engagements that are supposed to pressure the opponent into making things other than drones. You can't really turn back with tanks the same way you do with mines or hellbats. If you set up to do an attack with tanks you pretty much had to commit to a engagement. Tanks aren't really viable as a support unit anymore due to the speed and regen of mutas that can effectively pick of key units without large losses.
Instead terrans opt for one of the 4: bio hellbat thor, Bio hellbat, bio mine, and bio mine thor. Thors are generally only added when zerg is playing with large muta numbers, the "rule" is to add thors if they go above 20. From a zerg pov it might look similar in terms of unit comp, but the ways you have to adapt to different timings are massive, you have to be a lot more active in scouting in the current meta.
My major issue with SH is how hard the upgraded mothership makes locust borderline useless, combine this with tempest picking off static, while you warp in 3 dt's and 5 zealots from a prism on a map larger than overgrowth? Yeah, that zerg is in for a rough ride... If you have issues with mutas you should look at how Puck dealt with Zansters muta switches at IEM. Those games just made protoss look more broken than zerg in WOL.
