The thing with Cambodia was everyone was out to play. More so than a normal cast of returnees, because these players were motivated by the fans. They were there for themselves and nobody else. There were core alliances that stuck together, but none of those alliances were able to gain the majority. There were tiny alliances that moved around the game to progress themselves. And nobody held it against someone if they voted out someone from their alliance (think when Spencer voted Stephen out, but Jeremy wasn't really upset). There was a core alliance of Jeremy, Spencer and Tasha that made it to the end, but they did break away from each other in order to progress themselves, as well as each other, when the opportunity presented itself. These things were all magnified by the number of tribe swaps. There wasn't time to develop solid, strong alliances, meaning those who were able to adapt to the constant shift in votes were the ones who made it far, such as Jeremy, Spencer and Wentworth. Those who were stuck in their own ways, like Savage and Fishbach, were taken out sooner rather than later.
So I think voting blocks were a real thing, it just wasn't the intended strategy. However, it was definitely something that the players needed to maneuver through in order to succeed. And finding a balance between alliances and voting blocks was ultimately the thing that won Jeremy the game and got Spencer (and Tasha, though she was dragged) to the end.