Personally for a file server I'd switch to the Nas4free/Freenas OS instead of Windows 10.
Nas4free/Freenas are based on FreeBSD not linux
Even with Windows 10 Pro you still can't have more than 20 people connecting to a share at the same time, in order to encourage businesses to upgraded to Windows Server.
Nas4free/Freenas has no such limitation.
Nas4free/Freenas is a much better performing file server than Windows 10 due to the ability to use the ram of the computer hosting the data as a read cache, called the ARC, along with transparent compression of data, LZ4 compression is most popular due to its good compression and low cpu usage. (The i3 I use for my NAS4FREE running as an ftp server works perfectly even when saturating its gigabit connection.)
You can even use a solid state to increase the capacity of the read cache, called the L2ARC, or add an optional write cache for times when the NAS will be used for heavy writes, called the ZIL.
There is a bit of a learning curve, but once you have it all setup you won't need to buy another off the shelf nas again.
For instance, lets say your computer has 32 gigabytes of ram.
1 gigabyte is reserved for the OS, NAS4FREE in my case, and the rest can be used for cache'ing commonly accessed files.
This gives you 31 gigabytes in read cache, ARC, that can be accessed from ram instead of the hard drives allowing for incredibly fast reads, limited only by your gigabit/10gigabit connection assuming the data is in the cache.
Adding a solid state allows you to extend your ARC with an L2ARC.
Lets say you added a 256 gigabyte Samsung 850 Pro, this is layered behind the 31 gigabyte arc allowing for more files to be cached once you exceed 31 gigabytes.
It won't be as fast as reading from ram, but much faster and lower latency than having to read it from a hard drive array.
You can also use deduplication if you have a need for it.
Assuming you have enough ram or L2ARC to contain the dedup tables.