Darth Sidious with weak defense?

I took some advice from the forum here and focused my energy on Sid. He 4*, gear 6 with Ability levels 3, 4, 3 and 2. When I put him in leader mode (paired with other Jedis), and he gets a couple of hits, he turns yellow. I had a Resistance pilot sniper take him out with a quick shot and quick turn. Had a Dooku turn him yellow quickly too. I'm wondering if I should put more defense in Leader position versus evasion or critical chance. This was in the Squad Arena. My opponent was 1 or 2 levels below me too.

Any suggestions? Dathcha suffers a similar problem.