Max,
You may also want to consider using the ‘properties’ to serve your needs. You could e.g. define a set ‘phones’ and another one ‘cameras’. Then for phones you could define a property ‘type’ with values ‘phones’, ‘cables’, ‘chargers’ etc.
Frontend-access to the properties is easy by using facets, but you could also mirror them by means of product-feed-based categories for access via a category tree.
Cheers,
Geert