This is part of it, but not the entirety of the issue. The worry isn't that the Cubs are going to take a bunch of curveballs for strikes, but that they're going to chase them out of the zone. It's more a worry for the back half of the lineup than the front half, and it's more of a worry the better a breaking pitch that you have. Tomlin's curve sits somewhere between Bauer's and Klubers on the quality scale, with more risk of him being like Bauer than upside to be like Kluber, especially on short rest. It's also good to remember that for all the hand wringing about Tomlin, in his outing where everything went right he still only went 4.2 IP. That's probably the best shot the Cubs have considering the Indians can pretty easily get 4-5 IP from Shaw/Miller/Allen, but the other half is still an opportunity. Shaw has given up 3 hits and 2 walks for a run in 3.2 IP. Miller has given up 5 baserunners(including a HR) and multiple lineouts in 5.1 IP. In a game where the Indians very easily might struggle to score 3, the Cubs don't need to bomb Tomlin into oblivion to have the upper hand. I've heard that he abandoned his slider which was a really bad pitch for him, but I don't have the energy to actually look into it.