Depending upon the artwork, Symbols may be what you are seeking.
If you create one Symbol, you can then place symbol instances (duplicates) as often as you want. Editing the Symbol will result in all referenced symbol instances being updated.
To create a symbol, simply select your artwork and drag it to the Symbol Panel.
To place instances, simply copy the symbol on your artboard and duplicate it somewhere else. You can also drag from the Symbol Panel to any artboard and it will "drop" an instance of that Symbol.
To edit a Symbol, simply double-click it in the Symbol Panel.
Referring to artboards, yes You can stack artboards on top of one another, overlap them, or anything you need. However, layers are not directly associated with artboards. So you have to watch for overlapping artwork if you wish to have separate art on the various (overlapping) artboards.