Yes, the spellbooks not only shallow, but lack any distinct 'feel'. in MoM Nature indeed felt different then chaos or life or death. Here spells are similar to each other but with different names
Overall I agree with OP. Let's take a look at champions in EWOM, they are bland. Moreover all heroes level up in exactly the same way - I mean you can add a bit of this a bit of that, but as result they are not much stronger then your generic soldier, but your squad of soldiers will be anyway more effective. Now lets look at MoM why heroes where fun, because every hero is different they had own set of abilities, and they not just increased base stats but their spec abilities a