The approach treats animal companions as a style for two reasons:
- Companions are powerful. Companions can deal as much damage as a character and have about the same chance to hit. They aren't weak and since extra attacks (particularly extra attacks without penalties) are hard to come by, that makes them powerful.
- The role of styles is to silo powerful and complex powers to ensure the game doesn't get too muddy. Animal companions are an awesome part of RPGs that I want in the game, but they also add another figure to keep track of, another set of statistics, and another attack. We don't want to that piggybacking with too many other complex game rules.