@Dobo I believe most of the companies who are using NS as their main ERP either small to mid-size and companies who are big they use it mainly for Financials. So usually companies are looking for people who can do admin/development and integrations. Probably only few NS end users companies will have team of NS Admin/ Developer and Business Analyst except partners and NS suiteapp product companies

Does this mean a person should be able to do scripting while work as an admin?

it really depends upon the job description but an admin should have some knowledge of scripts to troubleshoot NS issues

Got it, you don’t need to be able to develop a new script but be able to make changes within the script

One of the quickest way for a client to burn money is an admin who doesn't understand scripting changing script without telling us exactly what they have changed. If you work with a partner closely, scripting could be an ancillary skill where rather than changing it yourself, you understand what possibilities are for solving problems with them.

why don’t they use a sandbox account to test it out first?

Even if they test in sandbox, I've seen people change stuff in a complex script, test their use case and not realize that it had other impacts.

this means the person didn’t do any documentations..

You can only document what you know...admins need to understand the system well enough to explain the impacts of changes made. Otherwise you might as well have some random person in finance click buttons and hope for the best