Fenris Master Plan

[Some]

Fenris's plan actually would make sense for a non-intelligent species, e.g. a virus.

The problem with humanoids is that they grow, acquiring knowledge and experience. The longer the lifespan, the greater their potential.

A species that's healthy and functional beyond Age 200 can easily have most of its population with over 100-years of magical training, political experience, military strategy, weapon-crafting skill, engineering knowledge, etc..

For example, how would 100 wizards (30 lvl-1's, 25 lvl-2's, 20 lvl-3's, 15 lvl-4's, and 10-lvl-5's) fare against a single epic-level wizard?

Except it wouldn't even be that equal. For example, the low-level wizards would come from a society that wouldn't even know what high-level spells were; they wouldn't even know what the epic-level wizard could do to them, much less how to strategize against it. Plus they'd have sharp disparities in their equipment, training, and cultural norms, all strongly favoring the epic-level wizard.

Fenris's strategy doesn't work for humanoids.