I have started out with a standard Spirit/Lore deck, but am considering switching over to a three-sphere format.
The main problem with Spirit/Lore is that I am chronically short on resources (and I refuse to give in to abusing the Zigil Miner combo, before anyone suggests that!). I would like to switch over to Leadership, which with Steward of Gondor generates plenty of resources, and Leadership has much better ability to deal with heavy combat, where Spirit/Lore really falls down. The problem is, I am heavily dependent on a few Spirit and Lore cards - e.g., Northern Tracker, The Galadhrim's Greeting, Henamarth Riversong, Forest Snare, etc. - and can't see Leadership/Lore as being viable, and Leadership/Spirit alone as being only just barely viable.
So I am seriously considering a three-sphere deck, but the question is, what is the best setup for one? I am thinking keeping Heroes in two spheres and using Songs to add the third sphere in, which I suspect is the standard approach (three heroes from different spheres could make the first few turns exceptionally rough). The question then becomes what to make the primary sphere, which the secondary sphere, and which the sphere last to be added. My instinct is to go with Leadership as primary, Spirit as secondary, and Lore the last to be added, but I could just as easily put Spirit first.
Any thoughts on the three-sphere deck, how well it works and what the optimal configuration is?