I hope this 7.2% of the population gets to talking. Saving for retirement is important, and if a couple has to shift its finances around to ensure that both parties are stashing away an appropriate amount of money for retirement, so be it.* The couple has to have that discussion first, though.
*Presuming that the partners collectively make enough money to properly fund two retirement accounts, that is. The fact that many couples (and singles) don’t make enough money to properly fund retirement is by far a bigger issue than couples who have retirement accounts not talking about their exact contents.