After players collect taxes, cull the number of Power Tokens in each player’s Ally Pool down to just 2 tokens per non-player house, returning excess tokens to their House Mats. This will not cause any alliance changes. For instance, culling a third Tyrell and a third Arryn token from your Ally Pool.
If a player controls King’s Landing and now has more Power Tokens for a house they are not allied with, that will be resolved when Checking Alliances at the end of the next round.