Staking dilemma

[THAY3R]

Scenario :

Staking team is built of 3 backers, A, B and C.

A has a horse from before the team was formed. Let's say he has 9k in makeup. A wants to bring him onto the team, what amount should B and C pay for this right?

It seems to me that theoretically if horse gets out of makeup 100% of the time, B and C should pay A 3k each. Of course this is not a certainty, hence the dilemma.

My brain has exploded thinking of what to do.

For the love of [censored], MTTC help us!