network attached storage – Pros and Cons of volume layout when moving to a NAS architecture

I currently have a Windows 2008r2 server with about 24 TB of storage on 10 physical drives.
I’m planning to replace the server and move the storage to a NAS system.

Currently the 10 drives are organized for specific (historical) purposes.
For reliability, I’d like to organize the new NAS system as a single RAID-5 or RAID-6 array. With 5 8TB drives in RAID-6, I would have 24 TB available.

But I’d also like to maintain the shares and volume structure of the existing system.
One approach is to partition the RAID array into volumes emulating the current structure.
Another approach would be to create top-level folders corresponding to the old drives, share those with the same share names and policies, and set quotas similar to the original drive sizes.

What are pros and cons of each approach? Are there other approaches that can provide structure and isolation and limit space consumption, while providing more flexibility compared to fixed partitioning? Are there any recommended resources for learning about this topic?