Yes, he can do executive orders. The courts still get to judge whether they are legal, though... some months/years later.

For the more egregious ones, there are temporary restraining orders... days/weeks/months later.

So, yes, he can do that, and yes, he can be overruled on them, and yes, that happens after some damage has already been done.

The executive can't enforce laws that don't exist

A president cannot (legally) use an EO to create new laws that bind private citizens or businesses. EOs can only be issued to federal agencies, and only Federal Agencies & Employees (and federal contractors) are bound by direct compliance of an EO.

Now that Chevron is no more, EOs are even weaker than they used to be because the regulatory agencies no longer have teeth.

Premature compliance != legally required compliance. Anyone complying early to an EO when they don't have to is an idiot.