I never fear Carriers because I always ave Defilers on hand, about 6 or 7. Because most people don't spread out their Carriers and attack in diff locations, I use Plague once and it infects them all. Then comes Dark Swarm with Hydra's. and while their worried about attacking me I sneak in some Cracklings that I have stashed away in an Overlord somewhere.
And besides that look at the time factor and money factor of the both.
Heres a lil table I wasted my time doing.
Toss as 1 Stargate and Zerg have 1 Hive.
Time for 1 Carrier = 140s
Time for 3 Hydras = 28s
Cost for 1 Carrier 350min/250gas
Cost for 3 Hydras 225min/75gas
Supplies for 1 Carrier = 4
Supplies for 3 Hydras = 3
Time for 6 Defilers 300 secs
Cost for 6 Defilers 300min/900gas
Supplies for 6 Defilers = 12
Now if both max without any other units..
50 Carriers
188 Hydras/6 Defilers
Total cost for Toss:
Carriers = 17,500min/12,500gas
Total Time:
Carriers = 7,000s
Total cost for Zerg:
Hydras = 14,100min/4,700gas
Defilers = 300min/900gas
Total time:
Hydras = 1,736s
Defilers = 300
Results:
For max Carriers is 17,500min/12,500gas and 7,000s
For max Hydra and 6 Defilers is 14,400min/5,600gas and 2,036s
Toss 3,100 more min/6,900 more gas then Zerg.
Toss waste 4946 more seconds then Zerg.
Toss have 144 units less than Zerg...
So basically Toss will be wiped out by Hydras before he could max.