Are Poison Aura Summons Worth It?

[Cor2]

In sp I often make posion armies. Monster Toads as infantry, bog beasts as skirmishers, maybe some vinemen, lead tham with nature mages. Its pretty easy to do if you have easy access to nature. Fun to watch the posion cloud take up most of the field.
But the armies always take heavy casualties. They don't last long, even with buffs like mass protection and mass regen. So i place most of them in the "just for fun catagory. The major exceptions being Catoplebas and the Big dragon thing whos name excapes me at the moment.