Not that it’s really a balance issue but on certain maps you can also literally go BC Liberator with no ground units outside of a few safety tanks and bunkers in TvZ and smash the zerg hard.
Want to know why?
Because Liberators have 3 things going for them
- They deal imbalanced damage
- They have AtA splash damage
- They have long range
Hydras become a good way to lose the game, air units must be pre split vs mass Lib BC as well - and even then, once there’s enough Liberators they will 1-2 shot massive clumps of Corruptors, pre split or not.
The only answers are literally “try to base race the Terran and have enough air units to kill the floating buildings before your army is wiped out” or “Get lots and lots and lots of Vipers because PB is your only recourse”
Liberators are a problem unit and they always will be unless you make them flying Reapers; where you get 1 of them and then forget they exist after.