The blasting banker would be more like an archetype than a build, woldnt?
I mean, the concept is adaptable for different mages and it has a strategy on its own, different from the others (turtle or rush, in example).
In that case, I believe it is perfectly available nowadays. Not obsolete at all.
Regarding banking enchanter, I tried something like that in jokhtari with felella, but I suffered a lot vs rush. The deck was slow to set up and had not enough areas. The bow helped but it can be dissolved (my last game with this deck my rival dissolved 3 bows).
You have to be heavily tooled vs rush, specially swarm rush. I came to 5-6 armor + veteran and still swarms killed me.
That goes for my jokthari, of course. Other enchant-heavy decks can do maybe better. But i find Felella is a nice tool for this, as she gives action and mana advantage, and can protect herself fine with glancing blow, dodge, etc. And I find jokhtari the best nature mage (felella is nature mage only) for this concept, as she can use some of the enchantments (hawkeye and akiro´s), and can use the bf quite fine (free action bow equipping). Also, the other 2 nature mages seemed oriented to creatures that somehow look like less worthy of enchantments.
If you try out another banker enchanter mage, please tell! I love aggrocontrol