What has worked for me is the following:

- let the most sr tech person ("the architect ") refine the stories maybe with the PM. Then, the same person will point the stories. - The sprint planning is only for presenting the stories to devs and giving some minor adjustments to the points if necessary - The architect may deep dive with a dev for a certain task while pointing it. - That way we have a standard complexity measure. We know different devs will perform different amount of points per sprint . We dont lose time in pointless neverending discussions - it also works well in Mexico where people are not so vocal so the standard poker planning doesn't go well