I respectfully disagree, but obviously I'm biased.
I don't think this line has ever had a major problem with chronic secondary pegwarmers, not to the extent of Legends or even the Vintage collection. You've got your Yularens sure, but over a period of months most of the secondary figures seem to cycle through pretty quickly. I don't recall Hasbro ever having to do a reclamation project on TCW like they have from time to time with the other lines (but I could be wrong).
Moreover, I think it's way to soon to draw any conclusions on these last 3 waves. Distribution is still somewhat spotty in places, and personal observances are apt to vary dramatically. You cannot easily find a Seripas or Armored Savage around here still. I think it's going to take some time before it becomes apparent what has and hasn't worked with these latest offerings. (El-Les certainly seems like the lead clunker so far, but this was an odd choice IMO, Season 3 Ahsoka or the Magnaguard would have been much better)
I just think it all comes back to character choices. Some one shot characters make for great figure choices, like Commander Jet, others not so much. I just think a character has to resonate with the fans for whatever reason, be it kids, collectors, whoever. The right figures will sell though, I am convinced, especially if released in relative proximity to the entertainment tie-in. (How many kids would love to be getting Krells right now?)
At any rate, Clone Wars stuff still seems to be moving so I can't agree with the logic to pull back on the line next year, but that stuff is out of my hands. What bothers me more than the quantity though are the selections. Even the few new figures they have previewed though seem incredibly lackluster, so I worry if those don't sell they will feel vindicated in their decision.
There's really no transparency to any of this stuff, so who really knows. It's a crazy industry.