I've got a explainer animation project about to start on which a animator and myself(also animator) are working together.
What I figured;
* Placing all the projects and assets files in a dropbox folder
* Animating scenes in separate aep files
* Have one montage.aep in which all scene.aep are imported.
* Increment and save option so that you dont have dublicate assets from all the scene.aep's.
Is this a doable option, or are there better ways to go about and do this?
Using a Dropbox folder is a good idea for the assets. Sharing the same project (aep) file is a bad idea and it looks like you've figured that out.
I would divide up the project by going over the script and make each sentence or at the most each paragraph a separate Composition. You could have several comps in your sep file. Keep the comps short and collaborate with storyboard sketches and discussions on how the transitions between shots will work.
I never try to do a project that is longer than a sentence or two in a single comp. It's just too hard to make changes, especially when you are working with a client.
As each person finishes a comp (sentence or paragraph) sent those comps to the Adobe Meida Encoder and render the footage to the dropbox. Assemble the final project in Premiere Pro. This will keep you working while shots are rendering, allow for easy real time previews of your combined shots and the final edit, and get things done faster. It wold be a very bad idea to try and combine all of your separate AE comps into a single comp in AE and try and collaborate on the final edit.