This can easily be achieved using two controllers. I created a second Xbox Gamertag, (Gold / Game Pass Ultimate not required), using an alternate email address, and made sure to add them as a Friend on Xbox Live. I then signed that account into the Xbox and pressed start while on the Main Menu, adding the second account to my party.
I created a Custom Online game, ensuring:
Game Type: Execution 2.0
Map: Any
Fill With Bots: On
Rounds to win: 99
Then in My Squad I made sure that my "friend / ally" second account was on the same team as my main account, and locked all slots on the opposing team. This results in an immediate win for the round, which is worth 5 honor for each round completed.
Each round takes about 20 seconds to complete. Using this method the achievement should be unlocked between 2 - 3 hours with no effort needed other than starting a new match after the 99 rounds are completed.