I disagree with you. At the end of the day they are just prospects. Just 1 example, obviously (there are plenty others) but the trade of Sebathia for Laporta, Brantley, Jackson, and Bryson. Brantley is a solid player (1 crazy flue season out of nowhere), but if you told me I get an ace for the playoff drive for a 2.5 win player for 6 seasons, I take that anyday. I'm not saying I'd trade a top 20 prospect for a rental, but I wouldn't hesitate to trade a lower 50 prospect with a lack of huge upside like Peraza/etc.
You're proving my point. The Brewers got Sabathia, great. He was phenomenal for them and they reached the NLDS. They then lost that in 4 games, in part because Sabathia gave up 5 runs in 3.2 IP.
For that, they gave up a haul that didn't even turn out that well. LaPorta did nothing. But even still, all they needed was one guy to hit, and for the last 4 years, Brantley has given them 15 WAR for a total cost of less than $8.5 million, and this year is only ⅔ over. He will end up over 3 WAR for the third time in that span.
I would do that deal all day every day from the Indians' perspective. Once you get into the playoffs and it's a game-by-game scenario, it's a crapshoot and no single player means all that much. Price has a small chance of getting hurt but an even bigger chance of not being much better than anybody else, as his playoff ERA of 4.5 suggests.
Those moves to add big names don't do much to increase your chances. Having even just Brantley has a bigger impact on your future chances to make the playoffs and throw yourself into that crapshoot.