Simultaneous Artist Team Workflow live on same project

Hi Guys

I originally asked this question over on the "Betas and Experimental Features" section. But I geuss it was the wrong section of the forum as only 1 guy replied, without actually answering I feel:
https://forum.unity.com/threads/sim...ow-live-on-same-project.1025098/#post-6643315

So I'm repeating the question here, which is hopefully the right place this time.

Preferably we want a solution for 5 artists. Likely no coding required as we will only be using Unity with the Unity Recorder for offline rendering.

Also, all 5 artists are in different countries. We have access to a Googly Drive Filestream where we currently share project folders for us all to access. We also have access to a Synology NAS.

Perforce Helix Core seems like a possible solution as its free for up to 5 uers. Its just not clear to me if we can use our own system for the storage, or we need to use their cloud servers for the storage. Wew prefer to use our own local storage (or or google drive)

I know Unity bought Plastic, but from the forum, seems that's a mess, plus its not free for 5 users.