I don't think there is just one quality that makes a good engineer. While someone may be considered a very good engineer when working in a certain position in a certain company, it is likely they would not excel in the same way in some other positions. Taking the extra time to make sure you understand a problem before diving in is not necessarily a bad thing. If it has become problematic in your particular job I would suggest you speak with your supervisor about what you can do to improve the situation. There may be some simple processes you can put in place to make everyone's job easier.