Hard to tell really. In 2008 and 2011 Manly had extremely good runs with injuries and in both years used the lowest number of players for the season. In 2009 and 2012, injuries hit hard and Manly didn't have the same consistency which affected their ability to build over consecutive games. In 2010 Manly, going into the final against the Dragons, had 14 players that were either unavailable or playing injured (in many cases injuries were enough to rule them out but they played simply to make up numbers). Manly showed last year that they have the talent to push for another title but injuries will come into play as they do for every team every year.
I think Toovey will start to make changes that will make this team his own, a change in his coaching style mid season in 2012 showed that he's a pretty capable coach. I have no doubt that Manly will be pushing once again for a top 4 finish. I also think some new faces in the squad along with those who were new last season (most notably Taufua) will allow Toovey to have more of his own influence on the squad.