BLUF: Orders are very important! Although the extent to which you give an order is left up to debate. Like many of the comments here, orders IMO should be one page. The order should have a schematic of what you are about to do (some would call this an overlay on asetate paper or on PP) one level ups commanders intent, your mission, your commanders intent, SOM (which is really the picture), tasking statements, and a CASEVAC plan. I believe this would give you subordinates enough information to accomplish the mission and work decentralized.

Shouldn't our orders be "mission type" that allow for decentralized execution which would support Mr Owens opinion which we need to make a decision and allow our subordinates the remainder of the time to execute?

We call it SMESC - Situation, Mission, Execution, Service Support, Command and Signal. I imagine each country has it's twist on it.

Terrain is briefed in the situation para, usually after enemy and friendly.
I agree. We use OSMEAC and we brief "ground" under Orientation to get everyone on the same page of where we are operating and what are the key terrain features that we will see/use.