Carver and Sorrow are so funny...
For some reason, they don't have problems understanding that a calm Hulk generates less power than an enraged Hulk, because that's the nature of the character.
But when it comes to the Sentry they absolutely refuse to understand, but probably more so accept that a mentally unstable Sentry generates less power than a mentally stable Sentry.
When Hulk is calm, his power, strength and durability decrease and when Sentry is unstable his power, strength and durability decrease. It's something that happens passivly. It's not up to them if all of their power goes up or not. It's up to their emotional / mental state at that point.
And while the Hulk can go from calm to angry in a short period of time, the Sentry does not have such luxury and has to deal with being weakened, since we saw him staying for days in his house and he would have continued to stay there, if the Hulk didn't threaten to kill the heroes and ultimately FORCED the Sentry to intervene.
So why are Carver and Sorrow being so stubborn? Because their favorite character the Hulk is being threatened here.
If we go by the events in comics, then we've seen an enraged and overall more powerful Hulk (World War) going fairly even with an unstable and overall less powerful Sentry.
And while the Hulk was supposedly pulling his punches in the entire arc, the Sentry was being dumbed down big time by the writer, who negated Sentry's superior speed so that the Hulk would have a chance.
Regarding the speed... Look at this comparison:
Hulk gets teleported few miles away and his enemies are super chilled out and continue to talk, because Hulk needs more than half a minute to run back:
http://static.comicvine.com/uploads/original/10/108566/4016401-01.jpg
And then we have the Sentry standing few miles away from the Punisher and appearing behind him, before Punisher even manages to finish his thought:
http://static.comicvine.com/uploads/original/11/116291/2179458-4.jpg
And you can't even make the argument that it's only limited to traveling speed, because Sentry has massivly better reaction and movement speed showings than the Hulk overall and everyone knows it.
Back to the topic of overall power:
We've seen a super enraged, not holding back Hulk completely unleashing (World Breaker) and destroying planets, while colliding with Red She-Hulk and we've seen a stable Sentry refusing to fight Genis-Vell on Earth, because he knew it would destroy the planet. When Genis-Vell teleported them to a more neutral battleground, they started fighting and destroying planets, while still holding back.
WW Hulk fought Sentry at his lowest. It doesn't take a genius to recognize that, only a hater or simply fanboy of threatened characters like Hulk / Thor.
@ One_Angry_Scot: THAT WAS REALLY IT!