When Randy Orton won the World Heavyweight Title completely cleanly from Chris Benoit, many people were shocked, since Orton and his Evolution stablemates were mega heels at the time, known for cheating at every possible opportunity, especially when it came to the World Championship. Then you realize, the reason Evolution didn't interfere on Orton's behalf is because they didn't want him to win. They just never thought in a billion years that young, 24-year-old Randy Orton could beat the man who Triple H had lost to at least three times that year, and once at WrestleMania.
The reason for him not working well in groups? It's due to Evolution, the people he trusted the most, turned on him when he won the World Heavyweight Title early in his career, and not being able to keep the World Heavyweight Title for all that long either and only losing it to Triple H, less than a month later and never regaining it until years later under different circumstances.
Why is Randy Orton so paranoid about the Authority possibly not being on his side? Surely it has much more to do with his own deep-seated confidence issues than it does with the fact that Triple H has already screwed him once.