A court can't issue an order to an army to surrender. A court can't force the president to nominate someone to be a federal judge.

There are some powers the executive has that can't be overruled by the courts. Now the question is - what?

In the case of OEs, there's a long history that they are subject to judicial powers if they are not based in law or constitutional powers. In the case of this specific EO, it's likely to stand but the rules coming out of it are likely to be challenged if they overstep the authority in law.

The examples in that article are legitimate examples. The more concerning part in that article is the suggestion of not following court rulings such as the myth of Andrew Jackson's SCOTUS quote.