When is shallow pruning possible in alpha-beta pruning for multi-player games?

I have read up on some research papers that state that shallow pruning is possible when sum of current node - upperbound of current player <= upperbound of previous player

However, what I noticed is that this only works when there is equal sum across all nodes.

Is it possible if every node has a different sum? For example, if 3 children have sums of 10, 15, 20?

Here is the paper I am reading: Multiplayer alpha-beta pruning (by Richard E. Korf, 1991)