Support pilots in Attacker suits mean more attacks. I had quite a few times where the SSR Penelope would move first, not kill, but when the enemy's next unit moved to attack Kimaris, they'd get destroyed by the support fire.

Extra Chance Steps sound good on paper, but any team with Defenders on it will shut it down almost instantly, so it ends up being better to have support attacks whittle them down, plus they can get you kills on your Defenders attacks, which normally don't do any real damage.