Endicott only lost because the strength of their team (a very strong backcourrt just choked). They were missing their best shooter and the two guards who weren't hurt went 4-20 from three.
Assie scored 21, but allowed the EC big man 22. I think Assie will get his points no matter who you put on him. That should not be the focus of your game. If you have solid guard play and decent perimeter defense, WConn isn't much of a challenge.
They are a strong team with good discipline and talent, but they can be beat with a disciplined defense and decent scouting.
Just so long as the post players don't run and hide, Cain should be able to wreak some havoc. It would be a huge suprise to me if WPI won by less than 12 or 15.