I never thought of doctrine as something for the very high levels, such as theatre command.

Doctrine or 'similar lines of thinking' are good for company to corps command, where there are great benefits to be found in having trust and reduced frictions because officers know that other officers think alike (just imagine Guderian working with a chief of staff or subordinate division commander who's of the French artillery school!).
(Another example, from small wars: Think of one battalion CO following a rough cordon + search + demolish + arrest approach while the next CO in the rotation follows a hearts + minds + indigenous militia approach. It won't work, it wouldn't work even if both approaches were correct!)


You better get your doctrine right and be ready for quick adjustments if much of your officer corps thinks along its lines, of course.