Hi NancyFor my use case, we work on many features at the same time and provide a priority order within the iteration for each team member. For the feature, I want to be able to see the ideal ordering of stories. For the iteration, I want to be setting priorities for each team member based on our iteration objectives. For instance, I may have someone helping out on some lower priority stories in an iteration for feature A, which for another person the associated feature A stories are their top objective and thus their stories from feature A are ranked higher in the iteration. We routinely have 5 to 7 features being worked on via their associated stories in an iteration.
I hope that helps to illustrate, why these two rankings should be independent.