Ivana to Wanda?! Why would you trade an awesome stop ability for a single power? Considering they play the exact same role in non SOA situations, and you would never pill either of them enough for that extra power to really dominate, I don't see the benefit. Not to mention Ivana looks waaaay cooler.
I agree with AaaBattery, Clover and Diana for Jayzel and Veronica, except for Ivana. She's real handy against SOA, and I see no reason to trade her for Wanda or any other 2 star card. Brittany is a decent alternative for Lucy, but Lucy is great for certain situations, say versus Jungo, Frozn or Vortex. I'd personally choose her over Brittany.
I really don't like Ella. At 5 power you have no options. She can't be pilled without being a giant waste, meaning she is very very predictable. Also, I actually really like Brittany. She's useful in that its not too big a waste to pop 2-3 pills on her, and your opponent knows that, and this will be unsure and may invest up to 3-4 pills at times.