One is still unstoppable when you get to the playoffs and face Bradley-like defending. One gets shut down with good coaching and defending come playoff time.
I was literally just about to post the same thing. While they're equal offensive players in the regular season, in the playoffs Isaiah is shutdownable/houndable.
People seem to be forgetting that Kyrie had LeBron--aka The Greatest Player in the World--to help him out, while IT's biggest offensive "help" was Avery Bradley. Teams won't be shutting down IT with Hayward around.
You do realize that IT played with Demarcus Cousins in Sacramento, right? And he didn't look nearly as good doing it as Kyrie has looked being second fiddle to Lebron.
Sure Cousins is no Lebron James, but he's still the best center in the game (arguably the best big man in the game, period).
And to me its not about shutting down IT, it's just about SLOWING down IT. All you need to do is make sure he doesn't go off for 30+ and you're fine. His defense is such a problem that for him to be a net positive, he needs to give you 29 points. If you can slow him down enough to limit him to "only" 27 points, then he becomes an overall liability.
It's really only when he's exploding for those big 31+ point games that his offensive becomes significant enough to overcome his defensive, and at that point he really becomes a threat.
It's very hard for a 5'9" guy to go out and give you 28-29 points every single night, especially in the playoffs. That's a difficult thing for a team to have to depend on getting night in, night out, for the next 3-4 years. It's going to be even harder to expect that once Thomas reaches his 30s and slows down a step or two, because at that point his defense will get even worse then it already is - at least now he has quickness and athleticism on his side.
Kyie, due to his size, isn't likely to decline nearly as quickly as Thomas. While Thomas is largely dependent on his quickness and explosiveness to get his shots off, Irving is more dependant on his size and skills - he's more like a 6'3" PG version of Carmelo. Even as he reaches up in to his 30's he should still be able to utilize his size, ball handling and shooting skills to remain effective (e.g. Jamaal Crawford) while IT's game is likely going to fall off a cliff once he reaches 30-31 and starts to lose his athleticism.
That whole "drop off" of IT and Horford is something that I am very seriously concerned about right now. This team as it stands only looks to have maybe 3 years of true competitiveness in it before the games of both Thomas and Horford fall off a cliff in the most dramatic way. In 3 years IT will be around 31 years old and Horford will be around 34. You're not getting much out of those guys by that point, so you're basically resting all of your hopes on Gordon Hayward and a handful of prospects to develop and carry that team through the future.
Getting Kyrie makes our future outlook much more favorable in the long term. Three years from now he'll still only be 28 years old - the same age Thomas is right now. By then Brown will be 25, Tatum will be 24 (both should be starting to come in to their own), Hayward will be around 29. That's a good core.