Escorts for Widowed Grandparents in Processional

In my fiancé’s family they include grandparents in the processional, which I am definitely good with doing. The issue I’m running in to is that we both have a set of divorced and widowed grandparents.
My maternal grandparents divorced and both remarried, but my my grandfather was widowed about a year ago. My paternal grandparents are both deceased.
My fiancé’s paternal grandparents divorced and both remarried, his grandmother was widowed some time ago. His maternal grandfather was windowed a couple years when his grandmother passed. Obviously those that are remarried can escort each other, and we have a male usher that could escort his grandmother. What I need advise on is how to have our widowed grandfathers go down the isle. Should they walk by themselves, by themselves side by side, or could I do female ushers for them? I know that’s not necessarily traditional, but we’ve got a mix of traditional and non traditional going on anyway so why not? LolThank you all in advance for any advise!