Generally this is true for *all* the registries. Mostly because component + helper registries expose their contents on the containing object. All of the registries do allow customizing the object alias, so if you want to load two Foos you can do:

```php
$this->addBehavior('Bar', ['className' => 'App\Model\Behavior\Foo']);
$this->addBehavior('Foo', ['className' => 'Plugin.Foo']);
```