That’s certainly a very reasonable strategy to propose, especially with Rigard in tank position.
Yellow is my weakest color, though. I have Li, Chao, Leo at 3/11, Wu, and Danza. I’ll certainly color match a purple tank in general, but having no healer in yellow plus indifferent offensive heroes means I often find those raids more difficult.
So in this situation, where I thought I had loads of time, my reasoning was that two healers in different colors was the safest strategy. I went red becaus of GF + BT, and purple because of Proteus vs Viv.
Even using my general strategy, green would have been a better choice than purple, with Melendor giving buff removal. Like I said, though, I figured this would be a cake-walk, so I wasn’t sweating it too much.
I literally got no connectable red fill-ins for 15 moves, and insufficient purples to fully charge Proteus or Rigard. They were all sparse and scattered. If I had Wu instead and the tiles had been equally bad, I’d have been hurting too. It was just an evil, evil raid 