Absolutely not. While something that is overly long (that definition differs, I personally think that 400-600 lines, as rieom suggested, is far too long...more like 500-800 words) runs the danger of being tedious and should be broken into multiple series hubs, as long as it is written clearly and concisely then that is more important than the length. Taking information out just to hit an "optimal length" is counterproductive, and making things too brief could make them more difficult to understand. However, the key word here is "concise"...you should use exactly the number of words needed to convey your message, taking five pages to explain something that could have been done in one is a great way to lose readers. In short, as always, quality is the most important thing.