My friends and I have spent a fair amount of time discussing Nick Swisher. He brings a fair amount of power, averaging 23 home runs a season throughout his career.
It's one thing to say he hit them in Yankee Stadium, which favors lefties and offers an otherwise stacked lineup. But he has been pretty consistent even in his days in Oakland and Chicago. He doesn't drive in a lot of runs, but he walks a fair amount, and has a good OPS.
Some players drastically fall off after 35, but most good players don't crash. They may see a slow dropoff as they near 40, but at 35, without major injuries, a player will likely not lose more than 10% off the average.
It's different for power hitters than fast players. Guys that depend on speed can go all at once. I remember Brady Anderson, who the Tribe picked up at the end of his career. When his speed went, he had nothing left.
The rest of the outfield doesn't scare me. The pitching scares me, but that's as a Tribe fan. More later.