Are there common patterns or best practices in planning which towers to maintain, based on resources they require? I mean, legacy/lumber, elemental embers (flaks), electrum.
I am at level 444 (Abyssal tier), so I maintain 10 towers. 4 are flaks, 3 electrum (2x orrery + howitzer), 3 legacy (mages). They work well, but it feels like maybe I locked myself too strongly into claiming the electrum branch every season, which limits my ability to claim other nice things, such as a good number of repeatable draconic chests.
At higher levels (550+), I would probably have to add legacy towers mostly, like 3x lightning, because of the maintenance costs.
If you have no general advice, perhaps you can share your level and balance by element, and what tradeoffs do you have to make to maintain it?
Edit: Most people agree that the electrum branch is good to claim fully or at least partially anyway, and as long as I do that, three electrum towers are viable. Accepting the first detailed reply as solution to give some due credit. Thanks everyone!