A Professional Outliner: duplicates naming policy + better UX

Working in a professional game environment, larger companies struggle to integrate Blender in their main pipeline.

2 pipeline streamlining problems:

1) Flat naming organization

Since every object, in any collection, can't have the same name, but get a ".001", that makes game assets cumbersome to handle when they (commonly) include implementation meshes: colliders, shadow casters, destruction meshes, custom navmeshes, occluders, anchors, etc.

Respecting the game's naming convention is crucial for automations in game, and documentation doesn't need extra awkward notes.

This limitation forces the company file organization into 2 scenarios: either have one blend file per asset, which is not ideal when you need agility between similar assets; or, make an addon to rename meshes on export, and instruct artists, but that is prone to errors as it adds the addon's criteria to respect.

(Also I wouldn't see any scenario that benefits from a flat naming organization, even outside of games, unless that facilitates other pipeline software that requires flat - which I never heard of)

2) Inability to manually sort objects, lack of drag&drop across "groups", hierarchy selection issue.

• You need to sort meshes when you deal with a large number. If you have 20 game assets, of which the team iterates only on the main object (and ignores their colliders etc), then you want the main object group of each asset to stay at the top and expanded by default. Or, if some objects are WIP or have old versions, the user may keep them "just in case" (eg: an outsourcing studio may play it safe), and would push them to the bottom+hide.
• "Empty" objects parenting meshes are the closest thing to "groups" in Maya (not collections), but the user can't drag and drop them easily across them. That is cumbersome in many specific situations I faced.
• The inability to automatically select every mesh contained in "group", but have to right click > Select hierarchy, adds to the documentation and human error chances.

As a "Blender-main" user who worked on a very popular game (company funded Blender), I had to yet re-confirm my company's pipeline on Maya recently, when we had the chance to change it. The outliner was a major reason: implications in a professional environment (even a small company) can be surprisingly problematic and pile up technical debt, so, ability to streamline and reduce human error is paramount.