The magic system is largely the same in 4th so this is more me explaining why I don't like the 2d6 vs 2d6 magic system in AOS. You might get value regardless.
but a low value is still better because a spell that casts on a 4 still succeeds on an 8 but not vice versa, thus it has better odds. There are two hurdles to pass, making the first lower makes it more likely to pass the second because the odds are zero if you fail the initial cast. With the way battalions work now, there's an inherent trade off that is relevant to spell casting. You take multiple wizards, you will have higher drops, but you'll also have more spells than they have unbinds, you can also afford to deploy a/all wizard within 30 knowing they will likely take first. Some armies will have access to low cast value unlimited spells that are impactful. On the other side units like Negash are basically guaranteed to get some spells that cannot be unbound and can help win the drop war.
I reckon I'll do up a couple charts to show what I'm talking about. Casting value does matter - but it's rare for it to matter. I like the point about battalions restricting the number of casts you might get and I definitely think the number of casts will be a little more important in 4th. The counterpoint here is that I'm not sure how much the turn order matters now. If you've got good wizards then it's probably fine to just play them and give up the turn order advantage.
