LE settings addon = embedded Samba *server*
Kodi settings = embedded SMB *client*
The current complexity is caused by Microsoft not ourselves, but it's not particularly hard to configure things as long as you stick to a couple of basic principles. The main one is that all connections must be authenticated with a username/password. The second is YOU CANNOT BROWSE from Kodi (on LE) to a Windows server so sources must be configured manually. I find it easier to manually edit /storage/.kodi/userdata/sources.xml over an SSH connection than fiddle with an on-screen keyboard in the Kodi GUI. The format is simple:
<source>
<name>MEDIA</name>
<path pathversion="1">smb://username:password@WINDOWS/MEDIA/</path>
<allowsharing>true</allowsharing>
</source>
Edit the user/pass and paths to suit - the format of the file is simple.
If you force Kodi to use insecure SMB1 the browse feature works. If Kodi uses secure defaults (SMB2/3) there is no browsing. OpenELEC "works" because it's old and outdated - the latest version is from May 2017 which pre-dates the SMB2/3 features being added to Kodi (after the WannaCry problems) so it's using SMB1.