Firstblade of Lord Aenoth says,
" {Skill} Choose an enemy at range 1-3 and in line of sight. That enemy must perform a speed-1 {march} ."
Metered March says,
"When moving, you may halt your movement at any point along the movement template."
If my opponent uses Firstblade of Lord Aenoth against my unit, and if my unit has Metered March, can my unit just stop without budging? I vote "yes" because Firstblade of Lord Aenoth is worded such that my unit is the one performing the march, which is movement, and that means it can choose to halt anywhere along that template.