I don't think you can compare last year's team and this year's team in terms of the second half and here's a reasoned-out answer as to why.
But first quickly in terms of over-playing the top guys with heavy minutes, I think that was true in the past but this year, the fourth line guys had a lot more playing time and there was a mix throughout the season at least on the penalty kill so the same players weren't out there time and time again. That certainly helped the team stay fresh as the year went on.
Anyways, back to some analysis. Last year's team did struggle in the second half. There were many different factors at play. Remember prior to the season the team went to Europe in August and played several games in Italy. Now at the start of the college season, the extra practice time and game experience in Europe helped because Colgate was far ahead of other teams development because those teams didn't have the extra two weeks or whatever it was of ice time and practice. But, as the year wore on, other teams caught up in development and for the upperclassmen that went to Europe, it became a really long year that started in August and briefly stopped for just a few weeks for finals and the holidays. There essentially was little to no rest and even the best players get tired out.
Also...the Ferris State trip was a setback that took a while to recover from. That first night, Colgate's ahead going into the third and then Ferris State storms back and wins. That momentum carried over into the second game and the psyche of the team needed a little while to bounce back. It finally did by the time Cornell rolled around. While the team was struggling in the second half, Colgate became essentially a one-line team with Smith-Wagner-Wilson doing the heavy lifting and the secondary scoring was dried up. When the Firman-Mayer-Prockow line came around and other lines contributed, there was more scoring. That top line simply couldn't do it all for Colgate. And in that second half of league play, teams bared down a lot more on Smith and forced others to put the puck in the net. And Austin's prolific pace was great but eventually the goals were going to dry up.
Now, as for this year, what happened? Well, you had a very young team. Sure, there were eight seniors but you had seven or eight freshmen on the ice every night and four of five sophomores. No matter how good freshmen are, they go through growing pains and often have times when they struggle. Offhand, I can remember Austin Smith as a freshman going nearly 1.5 months without a goal and Chris Wagner also had some of the same goal drought problems. Unfortunately because the freshmen were just such a big part of the offense, when they struggled, so did the team. No one else was able to pick up the slack and therefore, the team suffered. Now, going forward, those freshmen will evolve and adapt more to the college game and scoring shouldn't be an issue.
I could write more here but it's lunchtime and I need to eat something.
While it's frustrating to see the season end so early, the future is bright with all the great youngsters in the program.