**Updated**
You have two ways you can earn this achievement; there is no combined count factor here. I'll review both ways you can earn the achievement.
Option 1: Recruit 6 strike teams. This is easily the more time consuming option of the two; however it doesn't take much effort. In the multiplayer menu, visit "Strike Teams". Here you can recruit a team that you can send out on missions and upon success, they'll earn campaign items for your Pathfinder.
It is recommended that you download the "Apex HQ" application on your smart phone. It is a free app that you can link to your Xbox account. From here you can send your Strike Teams on missions from anywhere. Missions take real time to complete.
Your first strike team is "free"; so 5 to go. You'll need 40 "Mission Funds" to recruit your second team. You can earn "Mission Funds" by either completing Apex missions yourself, or by your Strike Team successfully completing missions.
After that, the amount of Mission funds required to recruit a new strike team increases by 40. In the end, you'll need a total of 600 Mission Funds to recruit 6 teams. The amount needed by team is as follows: 0, 40, 80, 120, 160, 200.
If you're in no rush and don't want to play the multiplayer at all, keep recruiting teams and sending those teams out on missions. They'll earn Mission Funds for each successful mission they complete. You'll earn more Mission Funds depending on the difficulty of the strike.
It is recommended that when you're ready to recruit your 6th team for the achievement; that you do it in game and not via the app.
**Update** It has been suggested by a few gamers that you may have to delete the original team you start with; and then recruit your 6th team to unlock the achievement. I did not run into this issue, but for those having trouble it is worth a try.
Option 2: Earn 25 assist medals in multiplayer. This is probably quickest option; but it will require some effort. You earn assist medals based on "assist points (AP)" earned in the match. 250 AP is a bronze medal, 500 AP for silver and 1000 AP for a gold medal. I personally used an Adept and got assist points like crazy.
Also, each medal is worth more points towards your total of 25. A bronze medal is worth 1, silver is worth 2 and a gold medal is worth 3 assist medals. Once you earn 25 medals, of Bronze or higher, you'll unlock the achievement. You can do this in as little as 9 matches if you earn all gold medals.