See title.
Just thinking about performance, if there are a lot of enemies and we need to get a Stat form all of them. Each one has to loop the stats Array to get the correct resource.
in a more complex game we would have more Stat (maybe even hidden one) that we need, to calc the correct damage.
On the other hand this way we could implement a logging mechanism to tell the dev he is trying to access a resource that is not deined.