I would say that to have multiple parts using the same definition now is going to cause problems.
With the introduction of attributes it is essential that the definitions are unique and relate to single parts only.
Copy the part name to the definition name-that way they match, can be easily found etc.
It might take some time to rework the parts & definitions but then you should be able to reload them quickly using the Actions\Replace/reload dialogue.
Using unique definitions will however open up a new world of useful attributes that can be used to save more info with the part such as:
datasheet hyperlink, manufactures & suppliers names and order codes, Value, wattage, voltage, package, company order no, FEC/RS numbers etc.
The more you put in the more you can get out.
My habit of using notepad died several years ago, the libed used to be awful - but the Library Editor now is excellent and I will only use notepad to open a corrupted library file (which is very rare).
BTW - using the library editor in V13+ means you can copy/paste parts including the definition to enable easy duplicating of parts and just changing the part/definition name.