Not a solution, but if you'd like to track your progress you can on the Halo Waypoint website. Go into your Wargames stats, narrow it down to Shatter and then you can select your weapon stats and it will list Mantis Stomps.
So go to the site -
http://www.halowaypoint.com/en-us/Wargames: Matchmaking
Maps
Shatter
Scroll down to find Mantis Stomps