If you could attach a save of a sovereign than can beat a Clambercoil before turn 50 I'd love to check it out. From what I can see they should have 270 hit points, 46 attack, 41 defense, 31 init, 87 accuracy, fear, fire breath, do 4-12 poison damage a turn to anyone they have injured, have their damage multipled by all the members of the defending group and have a really good spell resistance.
And that's the smallest dragon.
Shrink/growth means that Iranes attack would be doubled as she tries to chew through those 270 hit points and 41 defense. It's still going to be a long process. And shrink means that the dragon will have a 23 attack instead of 46. Still a daunting process, especially with that poison damage happening each round.
Blindness/curse both need to get through the dragons spell resistance (and curse only lasts for 3 turns). But even with his accuracy reduced to 43 he still has a breath weapon that doesnt need to make a hit roll and 43 attack when he does hit. curse is great against him for 3 rounds, but he still has 270 hit points to eat through when his defense is totally gone.
Not that I'm doubting what you are saying, there must just be some piece I am missing so I would love to check it out.