What do you mean by "creating dictionary in code"? You will have to set each dictionary key with an action on the event sheet. If you only need like 5 keys, I guess this solution is fine. But for 30 keys multiplied by 5 languages - that's too much code!
I want to switch to this solution because it is easier to have every language in a seperate file...
I actually did this in my first game and regretted it later. When there are a couple of hundreds strings in each file, it becomes really difficult to sync them, you need to make sure that the key names in each file are the same.
I now prefer putting all translations into a single array.