If I had to choose one, I'd prefer the string search. However, since Arena Mode's creature list is alphabetically sorted, it would probably be easier to implement the alphabetic organization...which would NOT obsolete the string search.
I don't know. The purpose of both the string search and alphabeticallization (is that even a word?) is to give us an idea of where to find a given entry in a list.
And while a string search is
very useful for long lists with complex entries (like the historical figures) it loses most of it's practicality when the list is alphabetized, since we already know the location of the entry we're looking for.
And vice versa, there is no point in alphabetizing a list when we can simply preform a string search to find the entry we're looking for.
Also, Dwarf Fort is already a relatively complex game, and it's only going to get more complex as development continues. So my vote goes to sorting long lists alphabetically for now, seeing as how the lists would only have to be sorted once (at the time they are loaded) and saving on those oh-so precious CPU cycles.
However, the string search function's usefulness compared to alphabetical sorting increases with the length of the list, so maybe someone skilled in statistics needs to do some science (the IRL kind) in comparing both methods.