When a sports team is inconsistent it's usually a sign the coach doesn't have control. At the pro level the HC doesn't need to give inspirational pre-game speeches (see Buono, Trestman) but the players have to buy in to his vision and competence to manage the game. IMHO the TiCats players didn't follow Marcel as a leader. I think his skills would be better suited to the CIS.
When Marshall was hired as HC many immediately condemned the move and I suppose were right. However, had that move worked it would have been brilliant. The killer was Taafe who was a great coordinator in Montreal but looked completely lost here as HC. Marcel was a mediocre coordinator, but I think his passport got him the job here more than his record.
Hopefully the TiCats have learned enough lessons; will hire the best available candidate and surround him with the best resources and support. Coaching is more critical in football than any other sport I can think of. There is enough potential among the 2011 TiCats players to win the 2012 Grey Cup, but it has to be managed and controlled properly.