PAAAASTE SPEEEECIAL
Copy your thing (grabbing multiple works), right click in one of your 2d views and hit
PAAAASTE SPEEEECIAL, select
"Make pasted entity names unique," and hit OK. This will paste it on top of the old one (unless you put in an offset, that is) so you can just drag it where you need. This changes all I/O to a unique value (incrementing a number at the end) but some certain things won't get changed, so make sure to double check. This can save you a ton of work if you plan for it and use it correctly.