WAR had access to Slashing even in ARR and the job was even more mandatory in Heavensward than it was in Stormblood. The difference with patch 4.2 was that it removed resource management from the job (and any semblance of skill, really), yet it let them retain their power imbalance. Suddenly you get an influx of players who don’t actually care about the job, but will play it because it’s trivially easy to play yet disproportionally powerful for the effort you put in. It’s bad for the job in the long run, but players ignore this out of short term greed.