He wasn’t in a combo in that first page, he reads Gai’s movements fine.
The 2nd page, that’s when he gets combo’ed, there’s a difference, that’s when he gets staggered, likely lost track of Gai’s movements.
Madara couldn’t move, that is also a factor he had to use a spherical barrier.
He failed to keep up with Gai, but that isn’t strictly due to speed vs reaction, there are a lot other factors involved, like the property of the attack, influence of previous attack and such.
People asked me to stop talking about Naruto here, so I’m going to stop here, you get it then you get it.