Numbered lists essentially reduce you to one primary key, the code. This can also present some challenges when moving system module properties of that list from one model to another because you have to reference the code. If the code is a made up value for the purposes of Anaplan then it really is not meaningful. It also then requires you to identify the system generated ID from Anaplan if the code value needs to change and is synchronized with another model. Good example would be Data Hub to Spoke application. If the code changes, how else would you know how to find the list value that changed so you can edit the code? Otherwise, you'll just be adding another list item.
If you need the ability to create list items from a dashboard you no longer need to use a numbered list. You can create forms in the new UX.
I remember reading a good debate between @rob_marshall@DavidSmith and @Misbah whether numbered lists are even needed. I'll see if I can find it. They may have some additional input for you.
I actually look at it the other way - Why would I use a number list? - In most of my Anaplan modelling I use normal lists. Even for "combination" lists as generally you are in control of the code and name, and the complexity around moving data between modules/models is a problem, as @JaredDolich outlined
So I only use Number lists when I need to take advantage of the specific features (display names, assign, copy, delete branch etc.)
Going forward, I'd prefer that we unify lists and only have 1 type, so taking the best bits of functionality from both
Yes, many reasons not to make your list numbered list (let's not talk about all). If you have duplicate names but unique codes in your list, that should be the right call for you to make it a numbered list.
All those 4 actions that @DavidSmith mentioned, you will have to use Numbered lists. I personally am not a huge fan of numbered list, to me general lists are more flexible.