Westmoreland strategy was ultimately based on one calculation..
America can kill Vietnamese faster than Vietnam can throw insurgents at Americans. Copying Falkenhyn , well, Verdun didn't win the war.
It's also led to a contradiction in strategy. When Westmoreland was in Vietnam, he consistently asked for more troops so he could not only fight the attritional battles he wanted (Battle of Hamburger hill), he needed troops to guard the border. When Abrahms requested troops to help the AVN secure the Hamlet program and guard the border, Westmoreland as a member of the chief of staff said no because overall strategic situation prevented sending more troops and the war was politically supposed to be winding down under Nixon.
Yes, but that doesn't negate
@fasquardon 's point, and if anything confirms it- namely, that Westmoreland's military strategy was dictated by political considerations and contradictory priorities. "Defeat North Vietnam and break its communist government" was never actually a realistic option for the US in Vietnam, because the US would be insane and stupid to escalate the war to the point where it was likely to draw in the Chinese (Korea 2: Electric Boogaloo) or risk the Soviets starting to rattle the sabre if, say, a Russian freighter got blown up in Hanoi harbor.
And this wasn't even a case of "the US could have won if it had had the will," it was a case of the US legitimately having higher strategic priorities that
could not be met by the US doing certain things in Vietnam... because they would result in "win the battle, lose the war" scenarios for the US in its overall global conflict with the Soviets.
And so the US lost in Vietnam.
But that point is basically exactly what fasquardon is saying- that
without those very specific geopolitical circumstances in your favor, or under different circumstances (i.e. you are fighting an enemy whose survival depends on winning, or who has no more pressing goal than to conquer you), the same strategies that served North Vietnam would tend to fail or at least not work out anywhere as satisfactorily as they did for the North Vietnamese- who paid a very,
very heavy price for their victory as it was.