With Unity 2017, we can use 2 tools to build Asset Bundle: AssetBundles-Browser and AssetGraph. I've created a test project here

General flow

1. Setup Asset Bundle Graph to build AssetBundles
2. Check AssetBundles with AssetBundleBrowser

Setup Asset Bundle Graph

The most basic setup consists of 4 nodes:

1. Load From Directory
2. Group By File Path
3. Configure Bundle From Group
4. Build Asset Bundles

In step 1, we create a folder that represents all resources related to an entity in our system, this could be a character or an enemy NPC. In step 2 we want to create one AssetBundle for each of the sub-folders in the parent folder. Each AssetBundle represents an aspect of the entity, such as by resource types: textures, materials, animations, or by enemy types: fast, slow. Step 3 applies naming convention to the AssetBundle's name. Step 4 is obvious, building the final asset bundles.

There are 2 examples of Asset Bundle Graph (ABG) in Assets/Tests: ABG_with_regex and ABG_with_wildcard.

In the ABG_with_regex example, we used the pattern /Missile\/(.*)/. There are several issues with this approach:

1. It's not real regex since we cannot use (.+) and we are forced to use (.*).
2. It creates group for sub-sub-folder. For example, it creates a group named Object/Materials instead of just putting it inside group Object
3. The main blocker issue is the error Moving file failed when building AssetBundles

In the ABG_with_wildcard example, the group is created correctly for each of the sub-folders. There is still some issues:

1. We cannot have . in the group name because if we do then the part after . will be considered variant.
2. We cannot have variants of sub-folder, we have to use the folder name itself as variant

This is just a rough test and obviously we require much more for an usable workflow.