Game theory is very complex.

Sounds overly complex to me. I like to keep things simple. Running down the price to gobble up even more SP, will just leave the holder will a bag of worthless STEEM as people will simply move on to another platform. The sentiment already is that too much SP has been accumulated by founders and early miners.

They can frontrun the whales. They can study what the whales like to vote for. It is the circlejerk effect so many people are mentioning.

Voting on posts before they are popular is the name of the game (if you're curating for a profit). Right now the game IS crude. "Popular" posts are simply posts that whales are likely to vote on. Front running isn't circlejerking, it's rational, if you are curating for profit.

In the future spotting popular posts will be more nuanced. There are already different group of whales with different voting strategies. I know this because I've studied them and I'm currently earning curation rewards at a rate of over 100% pa return on my SP, simply by pre-empting their behaviour. In the future, this will become harder and harder to do this as more or more whales invest or earn their way up the ladder.

My point is, any whale "pact" (or predictable behaviour) can be counteracted by those further down the chain. Any "pact" that solely benefits whales, will simply see the rational 'minion' or 'dolphin' bail on the project, they will obviously be clones and alternative to Steemit around the corner (with likely a more even distribution). I don't think there is a pact as, in my experience, people are fundamentally useless at them!

The whales will simply be shooting themselves in the foot by getting too greedy because unlike most cryptos they cannot just dump their bag. If they choose to cash out in freshly minted SBD, they'll be leaving a lot more acquired SP on the table.