You have to acquire the javelin during the setup phase.
When you spot the ATGM, your Bradleys should take evasive actions: smoke + move fast behind the hill.
Meanwhile, you pray and hope that your infantries spot and kill the ATGM with the javelins.
I was able to finish with 2 Bradleys intact.
During the last Lebanon war, the hezbollah's ATGM were very effective against Tsahal's armors.