SCL is not D&D, not 4E, not 5E, not any D&D edition. It was a crappy-money-grab-diablo-clone that fooled people to think that it was a D&D game.
Man, I miss NWN 2…
Only it is D&D. That's how dead D&D is. SCL is the most recent D&D game, it uses a very popular engine for 2017, it uses the latest official ruleset and WOTC approved everything they did.