Indeed we could get more information if we knew that ratio. The assumption here though is that World three is a future stage of worlds 1 and 2, but these two bear no relationship in that way. The three are intervals/stages of a different histories.
So actually that ratio is not defined.
The trouble I’m trying to point out is that if the FSM created the Tegmark4 multiverse, he’d still have to do more work to relate all these world stages that are disconnected by ascribing each pair a reality-fluid ratio. He would not need to do further work to get kilograms or daltons.
The function that connects two words W1 and W2 to a percentage has to be added. The same problem arises for personal identity as naively conceived. There are functions that will tell you, about any two agent intervals their: 1)Level of psychological/functional similarity 2)Will respond 1 if they are causally connected, and 0 otherwise and 3)If you are a phenomenalist—level of phenomenal consciousness interrelatedness.There is no further fact about personal identity, that is all we mean by Personal Identity. If another function was required determining 1 or 0 for each pair of agents and with the name “Personal Identity” it would be very suspicious.