Pretty much. Even if Mexico sends troops, they will continue to do nothing as they have been. It's a publicity stunt to appease Trump so that he can tell his sheep that he did something (even though he did nothing).
And when they do the tariffs will crush them. The people of mexico will not stand for lower exonomic performace based on Mexico unwilling to do anything about central american migration.
But i understand youre hoping it doesnt work as it invalidates your world view.