Damage with weapons

So recently I've been doing a lot more steel path and hard content and I've been wondering how I should build for big damage on single targets, should i use incarnon laetum as single target damage, alongside my incarnon latron for AOE? Incarnon latron does a fair job at taking care of pretty much all enemies except some bosses, demo units, liches, should I use laetum for that, and build into it? I kinda never built into secondaries cuz I assuemd they were small damage.