Although this is very opinionated issue, I would say no — at least for git.
- Git was not created as a storage solution.
- There's no way to merge image files.
- Therefore, branches don't make sense — if the only way to merge these branches together is to choose which version is correct, you're better of replacing the file right away.
- Git GUI tools are inferior to console, and are not simple. Do you want to teach your art team what the difference between commit and push is?
- When you checkout git repo, you checkout the whole history of all files, starting from initial commit. If you work on binary files long enough, the size will get enormous.
- Many git hosting sites, such as github, have limits on individual file sizes.
I think that you're much better off with dropbox.