It needs to be more than just treating the difficulty as being harder.
As well making enemies tankier can ruin the flow of the game. If the game plays a lot like a Swat game where you are meant to strike fast and hard, having beefy enemies ruins that and forces all battles into long drawn out fire fights.
Tactition mode made fights longer but the same strategies that worked on enemies on the easier difficulties worked on the newer ones. You just had to be smarter and change how you achieved it based on the enemies and battle layout, as well enemies have more of an ability to disrupt your plans.
