Yet another argument for a plan provision that allows for allocations pursuant to an "everybody in their own group" formula. You can always allocate comp-to-comp, if you want. And in this case you would not have to dilute the effectiveness of an employer contribution.
What surprises me is that you found "conflicting" information. Distribution options are clearly a 411(d)(6) protected benefit as it relates to funds already accrued. You can change it for future, but you have to protect the option for already accrued funds; you can't just eliminate it totally. Mike's answer is absolutely correct.