I've always wanted to the be top specialist in my own subfield. I realized at a certain point that I will never know if I have achieved that, because there is no official list, but that by having that as my initial goal, I have made sure that I am a name that must be mentioned in the conversation, at least. A somewhat grandiose goal helped me to achieve a modest amount.
If your goal is modest, that is fine, but generally speaking people come up a little short. I think a goal should be realistic but still a bit ambitious. That way, if you don't quite get there, you'll still have come further than someone who didn't try to do very much in the first place.
You might have to attempt to publish three articles a year in order to average one and a half. If you goal is three, you will probably publish one or two, but if your goal is one, you might not publish any. (If your goal is twelve, you might not publish any either. There is no point in setting a goal that's impossible.)
I realize most people don't think being the best person in a field is a correct goal. It sounds too competitive. Feel free to think in terms of non-competitive goals if you want. I'm just wired that way.