Comparing Kill at Northern Illinois and Edsall at Connecticut is apples and oranges. Kill took a program that was already really good and kept it at a high level (it had started to slip under Novak, but it was hardly a rebuilding project). Edsall took a program that was in the FCS and transitioned it into the Big East.
To simply look at their W-L records without any consideration of context is lazy at best.
A better comparison might be what Kill did at Southern Illinois, but even then the context is drastically different because Southern Illinois never aspired to be anything more than an FCS program.
Here are the predecessors to Kill and Edsall. Judge for yourself who was in decline and who was in the upswing...
Joe Novak (before Kill):
1996 Northern Illinois 1–10 6th
1997 Northern Illinois 0–11 0–8 6th (West)
1998 Northern Illinois 2–9 2–6 5th (West)
1999 Northern Illinois 5–6 5–3 T–2nd (West)
2000 Northern Illinois 6–5 4–3 T–3rd (West)
2001 Northern Illinois 6–5 4–3 T–2nd (West)
2002 Northern Illinois 8–4 7–1 T–1st (West)
2003 Northern Illinois 10–2 6–2 T–2nd (West)
2004 Northern Illinois 9–3 7–1 T–1st (West) W Silicon Valley
2005 Northern Illinois 7–5 6–2 T–1st (West)
2006 Northern Illinois 7–6 5–3 T–3rd (West) L Poinsettia
2007 Northern Illinois 2–10 1–6 6th (West)
Northern Illinois: 63–76 47–38
Total: 63–76
Connecticut
Tom Jackson (prior to Skip Holtz):
1983 Connecticut 5–6 4–1 1st
1984 Connecticut 3–8 1–4
1985 Connecticut 4–5 1–4
1986 Connecticut 8–3 5–2 1st
1987 Connecticut 7–4 5–2
1988 Connecticut 7–4 4–4
1989 Connecticut 8–3 6–2 1st
1990 Connecticut 7–4 6–2
1991 Connecticut 3–8 2–6
1992 Connecticut 5–6 4–5
1993 Connecticut 6–5 5–3
Connecticut: 62–57 43–35
Skip Holtz (before Edsall):
1994 Connecticut 4–7 4–4 3rd (NE)
1995 Connecticut 8–3 5–3 2nd (NE)
1996 Connecticut 5–6 3–5 4th (NE)
1997 Connecticut 7–4 4–4 T–2nd (NE)
1998 Connecticut 10–3 6–2 T–1st (NE)
Connecticut: 34–23 22–18