I see your point.
Maybe there's a way we could get both?
Thinking along the same lines as a planning bonus from HOI IV, give the player the option to set strategic objectives (push/hold/encircle) to redirect what a general may/may not have planned for already; however, what if there's a tradeoff in selecting a general with plans that match what the player wants versus a general with a very different strategy?
For example, if we have general with mountaineering experience wanting to flank an enemy from the heights, though the player orders them to focus on coastline objectives instead, the general will obey with a performance impact (better to choose a general that agrees with the coastal route).