I was able to find the four figures I wanted (Leia, Big Head, and 2 Stormies) in the wild last week, and I had a real good laugh at the failed accessory compatibility. Oh, the hubris of Hasbro, thinking they could just sleepwalk through these "primitive" designs! Leia does a little better than the boys with her gun thanks to the pincer-hand design, but if her arm points down it is still a 50/50 gamble if she will hold on to the gun for any period of time.
I guess these were truly meant to stay in the package.
Tarkin, meanwhile, is just fine.