I am not a cricket. But I will answer the question. Marlin's biggest problem is the absolute lack of ability to judge talent at the guard position, particularly at the 2 guard. I believe that his recruitment of EP was completely blind luck, but I will give him credit for recruiting him, and not call Marlin out for inability to recruit 1 guards. That being said, there are no competent guards at either 1 or 2 on the team this year.
I also question his game preparation, as we very often seem lost in the first 10 minutes of games; which would seem to indicate that we were unprepared for what the other team is doing.
Our offense has too much dribbling, not enough passing, not enough appropriate movement away from the ball, and is in general very static. I have asked several hoops coaches what kind of offense it is, and none of them have been able to identify it beyond "schoolyard".
As to in game coaching: see the last 3 minutes of the last couple of games.
What he CAN do is coach defense and get effort out of his players. Both of those are very good things, but if your guys are limited in their skill set [and except for Long and Washington, ours are], you have to be able to run an offense [see UALR] that gives them chances to get easy buckets.