I honestly find the only use for Spear (typically for me), is throwing it on myself before I refresh my own mp using Luminiferous Aether, only to decrease the cool down on the skill if I'm having MP issues (which doesn't happen often but it happens). I typically use Balance and Arrow on dps using extend or enhance, but again, situational. There's honestly been times where a player "knows" what they're doing, using their skills and cool downs correctly, but doesn't have the gear to do the damage needed to get the job done; I sometimes would arrow or balance on them to help them out if the other dps is pushing a good amount of damage, but i don't focus them. Bole I almost always RR or let it fall off (if I'm holding a card or have an effect that I'm saving for a card) or I shuffle it.

But let's be honest, there really is no definite right or wrong to using the classes cards. Here and now situations are unpredictable. Ast's can really only prepare for the possible future. So nearly every play style people use with the class and it's cards are going to constantly differ because we can never predict the unpredictable, only prepare for it. Literally Ast's card system is a perfect example of situational use and RNGesus.