Hmm... I don't disagree with you. Maybe I'll beef it up a bit more. I liked a few of your options that you used as well! Especially Colossal! Gargantuan just isn't big enough IMO!!! ;-)
I think I'll keep the Sorcerer hidden in my back pocket just in case it looks to easy for the players.
In about a week, I'll be running a one shot adventure where nine 20th level PCs will be going up against Tarrasque (Extra primed from The Book of the Tarrasque. HIGHLY recommend!). The players were allowed to each pick one Legendary item, plus some others too. Needless to say, I'm 99% certain...