It's a different market than it was when those pitchers signed.
The Tigers reportedly offered 6/144 for Scherzer, so they agree with you. Scherzer wants eight, so if he agreed on the AAV, he's looking at 8/192. I think that's where the disconnect is in this thread. We are arguing about pitchers who signed for different contract lengths, and in different years. If Scherzer signs for 6 years, he'll be around the Greinke total. BaseballReference has Greinke at 6/159. However, UN and I both think that Scherzer is getting more than six years. Because of that, and a slightly higher AAV, he's going to make more than the Grienke total.
You have brought up Verlander, Kershaw, and Hernandez repeatedly in this thread. The problem with that argument is that Verlander and Hernandez were not free agents. They were both under contract when they signed their extensions. Verlander and Hernandez had signed previous extensions, which locked them up throughout 2013 and 2014. They are getting less in those two years, than they would have on the open market. They also only had one team that offered a contract. If they waited until 2014, they would have been in line for over $200 million. As for Kershaw, his 2014 is under team control. He's making $22 million in 2014, which is far less than the AAV during the rest of his contract. He also only had one bidder. If he's still pitching at this level in 2018, he's going to opt out, and he's going to make more than the $215 million provided he signs for another 7 years.
As for the rest, Santana signed in 2008, Sabathia in 2009, Hamels in 2012, and Cain in 2012. Cain's 2012 season was part of a previous extension, which brought his value down. The market has obviously changed since then, which really makes these comparisons irrelevant.