Sure can simplify matters about figuring out which bucket to stick game elements in ... remember though D&D builds flavor around them concept buckets. (and some balance too)
Interestingly I switched the balance to the 'narratively driven focus' element of the game, so you rarely would be optimizing your character when the elements of that character arise organically from the narrative. In other words, the fighter slays the dragon and then his weapon becomes imbued with the power of elemental fire! You might have a back-and-forth between a GM and a player like "Hey, being able to do fire damage would kick ass, it will synergize mechanically with my XYZ!" but there are only so many choices about mechanical embodiment of that narrative available. The player could advocate for getting NOTHING, in the hope of engaging in some narrative that lets him spin up a frost brand instead, if that's what he wants, but you can see how that is not going to be a really ENCOURAGED sort of approach, as he's forgoing advancement. IME players are pretty eager to 'play along' with this kind of thing.
The other part is that I've tried to carefully write up elements in HoML to avoid artificial barriers between things. So you don't find a lot of boons where you only get some specific bonus to certain things, like 'melee weapon attacks' or something. Most things combine pretty freely, and stacking combinations of things together is in any case somewhat de-emphasized. A lot of this material would simply make 4e itself, with its reliance on preventing many 'broken' combinations via rules text, blow up and couldn't work. In HoML these things are OK, stacking quickly reaches a point of no more returns, and in any case if the GM and players WANT a story where all the characters become crazy super-buffed-up fire imbued engines of destruction that have every fire thing stacked onto them, then chances are the story arc will be filled with stuff which engages that and it will all be fine.
In terms of flavor, my approach is to lard things up with flavor, so you don't have to rely on the 4e approach of layering on a dozen feats/items/powers/etc in the same thematic space in order to get and maintain your character's mechanical and thematic relationship to a specific concept. So, you don't need a lot of flavor built around 'buckets', you can just pick an element that handles that aspect of your character's thematics and go on to other things. In fact, the REAL issue with HoML is more in terms of what do you need 20 boons worth of thematics for? You get a boon at every level, and many of them are fairly potent, thematically. So the bigger question is more like how do you find something new at level N that doesn't add TOO MUCH thematics to your character! I have tried to devise some boons that provide a more narrow focus, so you can go from being just a bad-assed spell-slinger to being a guy that manipulates the Rule of Contagion, to a guy that specifically utilizes that rule to confuse and disable people with shadow magic. Its not a really easy design concept though, and to some degree the system may be said to reward being a broad generalist who takes up the primary core boons of many different concepts and uses them all. If I can run a game up through many levels and a variety of PCs maybe I can figure out how to best make this balance work out, I dunno....