You don’t need profiles at all. You literally don’t need it at all. Profiles are a convenience to allow users to get jarfiles from the internet and that’s it. Whether you import a server from somewhere else or whether you use a profile–all that matters is that the jarfile is moved to the server directory, e.g., /var/games/minecraft/servers/myservername and select it as the “runnable jar”.
The first time you start a server with a profile, it copies the files from … /profiles/spigot_1.8.8 to … /servers/myservername. At that point, you can delete every profile and it wouldn’t stop that server from working because it’s already been copied to /servers/myservername.
Then whomever is maintaining Forge and the JSON file isn’t doing that great a job. 
That said, if you have any working jarfile from anywhere, whether you download it on your desktop and upload it to your server or whether you copy it from a flash drive, just put it in the /servers/myservername directory and it’ll work.