The following is a quote from the discussion section of "On The Viability Of Conspiratorial Beliefs" by David Robert Grimes:
"(...) The exponential decay form posited in Eq 6 would in theory yield the lowest probability of detection from a single conspiratorial event, but is likely unrealistic. The reasons for these are twofold—firstly, it implies that conspirators are assassinated or otherwise removed, which itself would be a conspiracy event. But perhaps more relevant is the observation that rapid removal of conspirators would itself likely create panic and disunity amongst invested parties. (...)"

The removal of an invested party from a conspirative circle would in all likelihood be the result of an effort to protect the rest of the circle and their goals. It is unlikely, that a decision of this magnitude, which indeed increases the probability of exposing the whole endeavor, is based on efforts to maximize the percental benefits for the remaining parties.

The removal of an invested party from a small conspirative circle would in all likelihood be the result of a consentaneous decision of the remaining invested parties. There is no reason to assume panic and disunity amongst remaining parties, especially when the act of removal eliminates a potential threat to the endeavor. If the threat is not eliminated, there is still no reason to assume panic and disunity, since it would require a calm and united effort to overcome the new obstacle. When the potential threat is eliminated through the removal of an invested party, the bond between the remaining parties may even become stronger, since they successfully decided and acted together for the sake of the whole endeavor.

A larger conspiracy requires compartmentalization and a high-ranking inner circle, within which the same logic applies as for a small conspirative circle. The removal of a low-ranking invested party would in all likelihood create fear amongst the remaining low-ranking invested parties, which, rather than causing panic and disunity, would motivate them to fall into line and enjoy the benefits of their investment, since the consequences of deviation were demonstrated.