I wouldn't necessarily lump them together.
Nash's skills determine the offensive style of the Suns, so he needs to lead the team in minutes per game, but his health and stamina are declining, as we have seen. Half of the Steve Nash we've known makes us mediocre.
He has to be in the lineup all of the time or none of the time for the Suns to succeed. And, as an example, with Gortat's commitment to work on his inside game on offense during the off-season, I believe he'll be a 15-20 point scorer next season, even without Steve, to go with the other strengths he has brought to the team.
Hill, on the other hand, is showing no sign of aging except scoring less in the second game of back-to-backs. With the development of Frye, Dudley and Gortat in the starting lineup, that one facet is not as crucial as it was when we depended on a one-dimensional Frye as well as Carter and Lopez.
And Hill is our defensive stopper, covering teams' offensive stars from the "1" to "4" positions. That's not just valuable, it's necessary, regardless of our sets on offense.
Hill wants to finish his career here. I would like him to.