I think you took in the wrong meaning what i said. I mean understanding the nature of the Job is very important. What ever you do there is some understanding to be made into the Job.
Anyone can say they know what they are doing
If a person understands that he is ranking a site for search engine he should be doing lots of learning into it and inturn will suceed. If a person thinks adding meta tags and titles will rank a site high then that person will never rank a good site, That is what I mean understand what you are doing, sit patient think for a minute what is the purpose of the job automatically 1000's of ideas will come into us which will lead us to the path to get the right knowledge of the nature of the job,
What ever we do we should understand the purpose, if we do it, we will understand the consequences,
And Yes checking the SEO companie's ranked search terms are very important it will also show what kind of techniques they use on the site, But again if a company is well aware of what they are doing that company will be a good one provided they use search engine friendly techniques,