I pity the engineers who use data in their design without prior verification. In simple terms, they do not know what they are doing. Secondly, if someone will ask them to defend their design, they will say, others used it. Or I used it in my previous projects.
Engineers, don't get giddy! Be firm! Always verify. Do not just accept data, find ways to confirm that your inputs into your design are correct. Always remember, rubbish in, rubbish out.
A good example was a design from a consulting company in the Middle East. It so happen that I was assigned to verify their design. I found out that the engineers have used data from previous projects. The documents where their data came from referred to an standard which they do not even have a copy. They just used the data blindly. So I asked them, what is the depth of burial for the cable derating factor you have used in your calculation. I got an answer that it was one (1) meter deep. Then I said, show me your proof. They could not. They do not have a copy of the standard they have put as the source of their data. Then I found out that they also have another standard which provides the same derating factor. I asked them, why don't you just use that standard? I got an answer, the other project used this, that's why we are using it.
Every project is unique, just like every person is unique. There are lots of variables that needed to be considered when performing designs. The more variables considered the better the design will be to suit the clients expectations. However, do not overdo as it will surely affect the project cost. It is best to just comply with ALARP.