I say just eliminate Legends - or just figure out some better figures to include in that line.
Yeah, the real problem with Legends was when they decided to go "kid only" with that line. Back when Legends was a 50/50 mix of kid/collector, it wasn't nearly as bad. It would be nice if they could pull some of those Plos and Saesees from the Legends line and replace them with collector-targeted figures.
Just imagine a plentiful source of Hoth Rebel Trooper v2, Imp Scan Dude #2, Rebel Tech (from Yavin BP), GeoArena Battle Droid, Evolutions TIE Pilot, Ewok 2-pack repaints, R5-M2 (from Hoth BP), other AstroDroid repaints, etc.
If they started packing in collector-desired army builders and some new repaints like they did circa Legends 2007/early'08, I think there would be a lot less people out there angry with the line. 
I agree with you here Jeff. Personally I feel the Legends line should either become an army building line, or if their going to continue to label it "Legends" then release those figures that would be considered legendary to the story. Saesee Tiin, not matter how good or bad the figure is, is NOT a legendary character in the SW universe. Neither is Plo Koon or Kit Fisto, and they happen to be two of my more favorite Jedi.
The term legendary needs to apply to the main heroes in this case. But that would make the line boring as there can really only be so many Luke, Leia, Han, Anakin, Obi-wan, etc. figs on the pegs at once, and then, not competing with the CW or realistic lines.
While I think most collectors would dread the overall line going to 4 sublines instead of three as it is now, I think in the case of Legendary it really needs to split to be those legendary characters and then an army building line. Call that one "Armies of Star Wars," or something on that order. That line could include both animated and realistic too.
Beyond we collectors griping though, retailors would be hard pressed to accept yet another subline of SW figures, especially when so many are lagging on the pegs today. (and Legacy is NOT one of those sublines that is).
So Hasbro really needs to rethink the Legends line.
If we make a reasonable assumption to say each wave will have 6 or 8 figures then each wave could be broken down like this:
6 figure wave:
1 OT Main Hero
1 PT Main Hero
2 different OT Army builders
2 different PT Army Builders
Again, main heroes are not secondary Jedi, cantina patrons, droids (except R2 and C-3PO of course).
Since cases come in 12 figures, just double these numbers to get the case breakdown.
8 figure wave:
2 different OT Main Hero
2 different PT Main Hero
2 different OT Army builders
2 different PT Army Builders
Since cases come in 12 figures, there can be two case breakdowns. More OT and more PT like this:
More OT:
2 different OT Main Hero with a double of each OT
2 different PT Main Hero
2 different OT Army builders with one extra each of OT army builders.
2 different PT Army Builders
for example:
Luke X2
Leia X2
Anakin X1
Obi-wan X1
Stormtrooper X2
Snowtrooper X2
Clone trooper X1
Battle Droid X1
For the PT case, flip the numbers.
At least this way there would be a ton of army builders, and plenty enough of the main characters, but virtually none of the secondary characters that aren't selling well as refreshed figures.
Back to the "Armies of Star Wars" thought for a second, I still think if this line were done it would be a winner, however, one key thing should happen-PRICE REDUCTION. The whole point of this is to be able to army build these affordably. If in the past Hasbro has been able to give us multipacks of 5 figures for $25 or less, then why can't single carded figs in the Armies line be $5? In totality they use no more cardboard then a battle pack does. Since the molds for those army builders have long since been created there isn't extra cost involved there.
I really think a serious reduction in price woud also help to bring back in many collectors who have dropped or greatly reduced the amount of SW figures they collect.
I'm speaking as a "reformed" army builder here. I used to buy 20 each of many troop type figures, sometimes even 40 or 80. But that is when figures were $5 or $6 tops. I can't justify building to those levels when figures are $8+. So I resolve myself to no more than 5 or 6 of a troop figure if I decide to squad build it (as opposed to army build it). And I know I'm not the only army builder who has drastically reduced the amount of figures he's bought. But you can clearly see even on me alone Hasbro is losing hundreds if not thousands of dollars. Multiply that by many collectors and we're talking hundreds of thousands if not millions of dollars that is lost to Hasbro and their retail partners.
Simple equation from above:
5 figs at the current $8 each is $40
20 figures at the $5 pricepoint is $100
A $60 loss or 150% loss just due to price alone.
I would think that if stores could sell us figs at $5 they would if they were moving 2 or 3 or 4 times as quickly.