Halo Wars 2

This achievement will likely come naturally over the number of online matches you play as Forge, but it can be done rather quickly in a solo Skirmish match against the AI (difficulty does not matter). If you prefer to knock this out quickly, head into the Skirmish lobby and make these setting changes:

• Gametype: Stronghold
• Starting Supply: 9999
• Starting Power: 9999

Once the match starts, build a Garage on your main base and then process to construct Grizzlies once you are able to. These tanks will take up eleven units, so you likely won't able to have ten on the field at once unless you increase your maximum population size. Regardless, once you have built at least ten Grizzlies, this achievement will unlock.