hmmm.. interesting question
I'll do the easy work... here are our records since Schiano has left. I think we need to add a few things to this to paint the picture with agreed upon facts. From there we can make jump to conclusions from more solid footing.
We should add recruting rankings for all years.. including Schiano's last years to identify trends. Then maybe offense and defense rankings.. maybe even APR rankings.. if eveyone adds something to this list it will be complete soon.
*2009 9–4 (3–4 Big East) St. Petersburg Bowl, W 45–24 vs. UCF
*2010 4–8 (1–6 Big East) **Eric Legrand injury year.. Keep Believing!
*2011 9–4 (4–3 Big East) Pinstripe Bowl, W 27–13 vs. Iowa State
2012 9–4 (5–2 Big East) Russell Athletic Bowl Virginia Tech L 10–13OT
*** announced Rutgers to join Big Ten (November)
2013 6–7 (2–5 The American) New Era Pinstripe Bowl Notre Dame L 16–29
2014 8–5 (3–5 Big Ten) Quick Lane Bowl North Carolina W 40–21
2015 4–8 (1–7 Big Ten)
2016 2–10 (0–9 Big Ten)
2017 4–8 (3–6 Big Ten)
My impression is that Rutgers' conference situation caused recruits to shy away from Rutgers even with Schiano at the helm.. and that is why he left... that and millions of dollars in the NFL in Florida.
So, until November of 2012, Rutgers recruiting classes would have been worse than when the Big East was more or less stable when GS was able to recruit well enough to get us to bowl games on a regular basis.
I think GS, with some retention of coaches.. would have done better than Flood did in those conditions. Better recruits than Flood but 2012-2014 results might be a game better each year.. I think GS beats PSU and Franklin at home in 2014 and that might have had a big and lasting effect on recruiting.
We would have been 6-0 going into the Ohio State game ( a blowout loss) and I think GS's D keeps it closer. OSU, Nebraska and MSU blew us out that year. I think GS keeps them all closer... maybe we get a better bowl with another win (vs Penn State).
On the field 2015 and 2016 might have been down years.. not sure we'd have gone to another bowl under GS.. because of the recruiting stream of several down-years in the past. Think we'd have won more games and avoided embarrassing losses.
I think 2013's recruits (to be frosh in 2014) would have been slighty better but 2014 and 2015 fully better recruiting the whole year as a Big Ten GS-lead team.
We'd be looking at a talented, experienced squad this year.. and quite likely scandal-free.
I know defensive side recruits would have a reason to come to Rutgers. And I doubt GS would have tolerated the joke our offense had become.
Under GS.. I think we'd be in a much better position right now. More stability in every area. More fan support, etc. And we'd definitely be looking at a bowl years by now as GS's recruits as a Big Ten team become upper classmen.