Kuhnhackl and Fehr both had 16% of their ice time with Crosby, Malkin or Bonino, which will go up when you consider Kuhnhackl with 3C Sheahan and Brassard in 2017-2018 and Fehr as the 3C when Bonino was injured in 2015-2016. Wilson had nearly as much time in the top-9 as he had outside of the top-9, he spent about 47% of his ice time with Crosby, Malkin or Bonino. You are correct with Rowney, Sullivan didn't even go that far (only 8% above the 4th line). So I'd say about 10% for Rowney, 20% for Kuhnhackl, 25% for Fehr and 50% for Wilson.
ZAR has been crazily used by the Penguins, with getting 57% of his ice time with Crosby, Malkin or Brassard (although it's a smaller sample size, since ZAR only has played in 33 games), and that will likely go up even further when you consider 3rd lines like ZAR-Sheahan-Rust. Sheahan is a little tough to look at since he was the 3C for as long as he was last year (which he deserved that spot) and Brassard has been hurt for a good chunk of his time here. Since Brassard's first game, Sheahan has spent about 121 minutes with Crosby, Malkin or Brassard and 379 minutes without either of them. He's at about 75% of his ice time as a 3C without Brassard or on the 4th line. Grant isn't even worth looking at because he hasn't spent any time with Crosby, Malkin or Brassard this year.
So basically, outside of ZAR (which everyone could tell you), Sullivan hasn't used vanilla players now any better or worse than he did in the past. When the Penguins have had 3 better centers, he has used Sheahan just like he used Fehr. He has used Grant just like he has used Rowney. He has replaced Wilson with ZAR and then ramped it up, but that's about it when it comes to Sullivan's over-usage with vanilla players.
Corsica | Line Stats
Eric Fehr's most common linemates in 15-16 were Cullen, Kuhnhckl, Wilson and....Sergei Plotnikov.
Tom Kuhnhackl's most common linemates from 15-17 were Cullen, Fehr, Rust and Sundqvist. Malkin doesn't even show up.
Kuhnhackl was used a lot in the top-9 with the Penguins last year, in 2017-2018. Over the full season, he played 36:27 with Corsby and 52:04 with Malkin. Before Brassard's first game, he played 92:04 with Sheahan. Kuhnhackl got crazy top-9 minutes last season, he was used nearly as much in the top-9 last season as Wilson was from 2015-2017.