wine-ge-8.26 is quite old now. Get the latest one, 10.something, and see if it solves your issues. Can't remember how you update Wine/Proton in Lutris. Protonup-QT is a great helper to get newer Wine versions for everything.

It's been a while since I have been messing around with Lutris. But the general way of installing WoW or any other thing is basically the same in Lutris, Heroic, Bottles, Steam or Wine without any helper. Though I would advice against using Steam because it creates a new prefix for every new exe you throw at it, unless you tell it otherwise.

1. You download the Battle.net installer from Blizzard.
2. (In most cases) create a new game/bottle/prefix (the prefix is like a fake-Windows drive)
3. Run the installer.
4. If everything went well, run Battle.net and let it install WoW.

Common problems (don't remember if they apply to Battle.net) are that you need to install the Visual C++ Runtime (vcredist), .Net Runtime and some fonts. You can do that with Winetricks or downloading the respective installers from Microsoft. You usually don't have to install all fonts, that'd take a long time. Arial or maybe Helvetica are usually enough.

That is exactly where I had to give up as well. It's the bad file descriptor error.