I've tried making different battle formations to win this mission, and god bless me I find that my lv6 officer with 42 machine guns (lv3) can kill them.

Here's my battle formation:

- - - - Lv3 MG*18

- - - - -- - - - - - - -

- - - - Lv3 MG*19

- - - - - - - - - - - - -

- - - - - Lv3 MG*5

Link to game: https://itunes.apple.com/us/app/revolution-2050/id512168250?mt=8

Use my invitation code:BM2UX9. I'm from USA SERVER1

Let me know if anyone has other tips to share or tactics that seem to be working for you in the game.