Industrial cabinet layout depends entirely on how the facility installation is to be done, and for practical purposes.
While it is common to feed power in (and out) of the top of some enclosures, it is also common to feed power from underground. Buried conduits are more expensive, but when excavating to do an installation, it is just as easy to put the electrical services below ground. That also makes for a much neater installation.
Control panel layouts are normally done so that components that may require interaction (drives, PLC's, scaling and control modules) are placed at approximately eye level. Things that are not typically accessed are placed either higher or lower. Interconnect terminal strips are typically at the bottom of the enclosures, unless there is a reason to place them elsewhere.
In summary, there is no actual code, or design rule about panel layout (aside from isolating high voltage from low voltage controls typically). Panels are built as dictated by the installation requirements.