We also have no idea what the break even point on these lines is for Big Chief. If, for example, it took 50% of stock being sold to go into profit, and they regularly sold 70-80% pretty quickly, then the fact that the remaining 20% is harder to move, sat in stock longer, and was subject to discounts isn't really an indication of any problems with the line going forward. We have been told before that they have to make a minimum run size, and it may be that the line is profitable, and it is just that selling all of a run takes a while. So while I'm sure they'd love everything to be a quick sell out, the fact that things aren't doing that isn't necessarily a sign that the line is in any sort of trouble.
On the flip side, if they are struggling to get into the black and make a profit from their releases at all, then that would certainly be cause for concern. But without access to the financials (which of course we will never have) then it's pretty tough to know from our position on the outside which of those is actually the case, short of them coming right out and telling us.
But given that Big Chief was struggling with securing enough capitol just to go forward in the early days, against the fact that in recent years they have expanded their deals with not just the BBC, but also taken on other high profile (and one would imagine, not altogether cheap) licenses as well, and now have James Bond on the cards on top of that, not to mention how much they have expanded their work as distributors of other companies releases in recent years, leads me to personally suspect that they are, more likely than not, sitting rather comfortably right now, all things considered, and that even the odd under performing release may not be anywhere near the threat that it once would have been. And as one of their highest profile lines, that Doctor Who releases probably aren't going away any time soon, and, as mentioned above, will probably only benefit from them having something as sellable as Bond should prove to be.
I mean Hell, they still have two Doctors and two companions up for pre-order, so while the release gap may be extensive, they don't seem to be showing any signs of giving up or slowing down, as far as planned releases go. And we could the the Eighth Doctor and Jack Harness pop up at any time for pre-order (my guess if just after the Ninth Doctor ships...whenever that is).
So while I sometimes personally question the logic of some of their choices, I think Who is relatively safe still, and that the Doctors, at the very least, would still each sell enough to be at least considered worth doing, without risk of taking a loss on any of them. Other characters, not so sure (but again, Big Chief should have a pretty good idea at this point how viable future companions would be, for example).
Maybe I'm overly optimistic, but I'm not too worried yet. Just wish their production turnaround wasn't quite so long, but then with the fall in the pound, and just how far in advance the decent quality factories tend to be booked (and by players making far bigger runs) there probably isn't a lit a smaller scale player can do on that front, other than trying to make sure that when it is their turn that the factory results are of high quality, and are worth the wait.
Just my take, anyhow.