Both coaches had very similar records at Moo U during their first two years.  In addition, both were Yankees, so Moorehead being a Yankee and not fitting in at Moo U is nonsense. 

Head coaching record
Year Team                    Overall   Conference Standing           Bowl/playoffs  Coaches#    AP° 
2009 Mississippi State   5–7        3–5             T–4th (Western)
2010 Mississippi State   9–4        4–4             5th (Western)  W Gator           17               15  

2018 Mississippi State   8–5        4–4             4th (Western)  L Outback         25
2019 Mississippi State   6–7        3–5             5th (Western)  L Music City

Mullens        14-11  7-9   1-1
Moorehead  14-12  7-9   0-2

The main difference is the envy of Ole Miss hiring Kiffin which caused the Moo U faithful to revolt and insist on firing Moorehead.