The combination of two below average offenses and long layoffs for each team have resulted in this very low total. Yes, neither team has played yet this month. But the oddsmaker has overcompensated for this in my view with too low of a total.  
The rust element also could factor defensively. 
Siena has three legitimate scoring threats led by Jaylen Pickett. The Saints have scored 74 or more points in 60 percent of their games. 
Niagara has averaged 73 points in its last three games. The Purple Eagles also have given up an average of 76.3 points in their past three games.