An article on HubPages is written as a response to what is typed in a search engine's (i.e. Google) toolbar. I suggest you take your long articles and condense them so that they:
1. Answer the query early in the article.
2. Capture the reader's attention so that they complete reading the article.
Some subjects require longer articles, some do not. Think of it as every word you put in your longer articles is important to the work.
Here's HubPages founder Paul Edmondson instructing a young Hubber in the early days of HubPages:
Hope this helps.
(Just kidding! The video is from A River Runs Through it, a biography written by Norman Mclean).