Now, I realize my previous post may have come off as spammy. For this I apologize.
Now, back to the point. This is what I've been working on.
Yes, the Sunflowers are to be removed in flags with Gargantuars or Gigas. And yes, the biggest threat to me right now are Dolphin Riders. It's not exactly easy to get the hang of timing for those little buggers. It's played basically like this strategy, though you need cobs to destroy Bungees in this one. Just maintain cob timing and you won't have a problem with Catapults. And how do we prevent Imps from chewing on those Winter Melons? Just place your cobs properly.