This is possible with the Non-Ultimate Erik and is very easy.
Start up a custom pvp in 3v3 on Dust
Move the left stick up and down to change the bots difficulty to trainer, after that choose Erik and a warthog and have buckys equipped.
When the game starts buy the first level upgrade and then buy 5 buckies
over all of the buckies and click
on the D-pad to send the buckies to capture the first base
After the first base is captured, send the remaining buckies from that fort to capture the middle base
By this time you should be able to buy the second level upgrade and when you have the option to buy the third level upgrade buy it ASAP
Follow them to the middle base and kill everything you can and after you kill them take out the 2 tanks above the middle base and take out the tank below the middle base
after you control the middle base make sure you make as many buckies as possible and send them to capture bases, but still try and roam around to kill as many enemies as you can
I would fill my Queue with buckies and while they were being built i would fly to the enemy base and take out their utilities around their base until my buckies were ready and then i would fly back and send them to capture a base and i would repeat that until i was level 9
When i reached level 9 everyone else was level 4,5, and 6
When you reach level 9 start sending buckies to attack the enemy base instead of capturing bases and you should reach level 10 right before you win and everybody else should be level 7 or below and you will get the achievement.
If theres anything i should add or remove from the guide just PM me or comment what to change, hope this help and don't forget to give it a thumbs up.