MachineClaw,
I would say that in the case of the characters that is really marketing. The whole idea of models w/ names etc... They probably have enough time in between for content development for the characters for them and third parties, frankly if they had it too short then it would upset the whole market based on these characters. While other factors can be at play space between is really a must for that model. I seriously doubt it has taken them 4 yrs to develop a v4 series of models.

No need to think outside the box....
    Just make it invisible.