Duplicate research exists, Artillery Shell Damage Bonus. The vanilla one exists and can be researched separately from the rampant version.

Drastically different research requirements as well. Also there is an artillery turret damage bonus from rampant which may also need to be removed, though it is not a duplicate since vanilla has no such research I think.

You posted in the wrong mod. However, yes, with the SA expansion, the artillery damage research should be removed

Ah...I did. I'm sorry.