Campbell Soup and Third Point

Cramer decided to break each situation down, starting with Campbell. Daniel Loeb and his hedge fund, Third Point Management, have been trying for weeks to replace the soup maker's board of directors and turn the heavily indebted company around. "Anyone who's followed Campbell knows that this current board has helped to destroy an immense amount of value, as the stock's been one of the worst performers in the food group for over the past decade," Cramer said. "I think [Loeb]'s right. Campbell Soup needs a new board of directors and the company should quickly put itself up for sale." While Campbell's "fabulous brands," its balance sheet was too broken to recommend the stock, Cramer continued. "As much as I believe in Loeb's ability to effect change, I'd rather just buy a food company that's doing well," the "Mad Money" host said.

Starbucks and Pershing Square

Starbucks, however, was an entirely different story. "The problem here is that I don't think Ackman necessarily has anything to offer," Cramer said, adding that his presentation offered "nothing new or revelatory: China should be getting better. U.S. can get better. All obvious stuff." In Cramer's view, Starbucks' business in China is already improving and the U.S. business won't see a significant upturn until the fourth quarter. Moreover, the company's aggressive buyback has been working, he said. "I've been saying that Starbucks is turning," he said. "But even after the stock's 3 percent pullback today, I worry about Starbucks the stock. I don't think this quarter will be all that great. So why not be patient?" Reiterating his earlier call for investors to wait for Starbucks's stock to decline from its inflated levels before buying in, Cramer acknowledged Ackman's previous successes, most recently with Chipotle Mexican Grill. "Admittedly, Ackman's done well with the restaurant chains," he said. "But here's the thing: activists work best when management is doing a bad job. Starbucks has good management — I think CEO Kevin Johnson is slowly but surely righting the ship [and] doing it the right way. I hope he's just not distracted by Ackman."

PPG Industries and Nelson Peltz

When it came to PPG, which pre-announced a sharply negative earnings report and forecast Tuesday before news of Trian Partners' investment broke, Cramer was speechless. "Frankly, I don't even know what to say about this one," he said, noting that shares of the specialty chemicals maker have "done nothing" since CEO Michael McGarry took over for former PPG chief Chuck Bunch, who happens to be a friend of Peltz's. "Earlier this year the company lost a key outlet for its Olympic Brand of paint when Lowe's stopped carrying the stuff. Ouch. PPG had a sloppy accounting scandal. Can't get my arms around it. Monday night, they pre-announced a huge shortfall in paint for automobiles," Cramer said. "Now, Nelson Peltz knew Chuck Bunch from the old Heinz board of directors. I bet he wishes that Chuck were back running things." "Peltz is very smart, he's engaged, but I don't think you can own PPG after such a dramatic shortfall. Even a brilliant billionaire might not be enough to protect this paint and coatings company from a slowing economy," the "Mad Money" host concluded.

Final thoughts

Here's where Cramer stands on each situation: Starbucks is a good long-term buy because the fundamentals are improving with or without Ackman; Campbell is a speculative play on whether or not Loeb can succeed in ousting the company's board; and PPG's deteriorating business may not survive even with Peltz at its side. "At the end of the day, though, these big-name money managers won't save you from a hideous market. That's not their job. Times like this are when you really need to do your own homework rather than piggybacking," Cramer said. "So just keep that in mind the next time you see some stock surging on a bad day because we've heard about an engaged or active investor getting involved."

WATCH: Cramer breaks down the market's 'activist stocks'