When Makoa is stunned, aim a bit lower on him to hit his head hitbox. Once you learn the location of his stunned head hitbox you'll see it's very easy to output high damage on him during his being stunned.
Inara's Impasse has very high health and can be annoying to take down, especially without Bulldozer. If the enemy Inara happens to use it near the payload, remember that if the payload touches it it will instantly be destroyed.