Well it's very different. Vyond creates full animations - moving people / transport etc.... I normally then add these illustrations into Captivate and overlay user interactivity that way...
One of the problems you may encounter is that you cannot overlay a Captivate object over a video nor an animation because those will always be on top of the stack. That can be changed with JS, but then you'll lose alll interactivity in the animation. A video is per definition passive.
Whereas with an Interactive video you can have overlay content slides and KC slides as I showed in that article.
Captivate works very nicely with Photoshop (roundtripping), with Audition, PhoneGap etc but if you start trying to embed items created with third party apps you may stubmle on many issues. That is the reason I talked about learning to use Captivate properly. A lot is possible with the included effects, you can use animated GIF's, OAM's etc.