Sony Vegas VS After Effects for graphic / Keyframe editing I want to animate "drawings" on people's faces like " X "'s and other lines and I am aware, as far as I know, that in sony vegas that is done via individual frames.

Is there another way? Does AE do it more easily?

As a general question which software is best used for editing or should a combination of software be used e.g Sony Vegas for final cut edits and then AE for post and graphic editing?
After Effects is definitely the right tool to use rather than Vegas for motion tracking / drawing on moving footage. Here is a classic tutorial that you can watch to get a sense for how to achieve face tracking &amp; replacement.

Vegas is much better suited for editing. After Effects can often struggle to achieve real-time playback over extended periods of time and doesn't have the tools built in the same way as a NLE like Vegas, Premiere, or Avid.