I understand the pacing structure as characters shift from being more exclusive and therefore more valuable, to becoming ftp farmable. Problem is that that structure kind of stops when they become farmable. Rogue one units, for example, are nearly 2 years old, yet are still consigned to 20 cost single hard nodes. Meanwhile you have Visas and Sion at the same rarity. Occasionally you'll find them in the guild events store, but not often enough to make much of a difference.
I don't mind the hard nodes, but as newer units start rotating in to the farming pool, these older ones should be reflectively more accessible by being put onto either multiple or cheaper energy costing nodes or both.
The less than what I would describe as "exclusive" character, Storm Trooper for instance, is still hanging around on a 12 and 20 cost hard node despite being cantina store farmable. He's far from the only extremely old unit wasting spots that should have something more recent on them. Just saying...
Removing rotating units entirely from the shard store was also imo a poor decision.