Most people find a boosting partner to just fly the edges of the map and help each other get the kills.You just have to watch for other people enjoying the fact someone is just sitting these waiting to be killed. Earn 3 Assault Ribbons, then: You Need a kill with a Pistol, a 40MM Grande, and the Defibrillator all in one round.
If you do the ones in a single round before you have three ribbons, it won't save.
So make sure you have 3 ribbons before you attempt to complete it.
When it was decided to release a patch early to address some issues, it was easier to leave it in rather than branch the code and then have to merge it later.
Is it possible that technically you don't actually need to do everything in one round but the requirements are resetting because the assignments don't have persistence, owing to the fact that they shouldn't be available yet?
After playing more and more hours, here is another strategy.
When you get in the bomber let your first 3 missiles fly right away in the direction of where you think the enemy is.
I would start with the shoulder missiles 1st and then try the mobile AA.
Update - I received this using the Stinger but many people are saying they are only getting this from the ILGA.
I would start with the defibrillator as it will be the hardest one to complete.
For the "Open Fire" assignment you need the three assault rifle ribbons before the other three requirements.