The Pens already had a solid offensive group with Syl Apps, Jean Pronovost and Lowell MacDonald when they added rookie phenom Pierre Larouche, young gun Rick Kehoe and veteran Vic Hadfield to the lineup for the 74-75 season, which helped vault them into 4th place in 75 and 2nd in 76 in GF. Veteran forward Ron Schock and their top blueliner Ron Stackhouse had career years playing on the top units with that group. Notable also was the presence of Battleship Kelly, who became one of the most feared, intimidating players in the game during his run with the Pens. For younger folk who missed him, Battleship was the Bob Probert of his day, a guy who would fight anyone *and* put pucks in the net.
They were shy of being an eltie team at the time because they lacked defensive depth and a true starting goaltender. After Jim Rutherford was shipped out, they cycled through Andy Brown and Michel Plasse, two guys who notoriously struggled throughout their careers. As mentioned above, there was also the coaching carousel, but it must be noted that there was a carousel in the front office, too. By luck as much as design, I think they just happened at the time to hit on a group of guys that gelled together at the right time, with that solid core of Apps-Pronovost at their career peaks playing with a couple of hot young guys, a few offesnive-minded vets stepping up for their last hurrah, and one of the toughest guys in the league riding shotgun.
Interestingly, the top-heavy, offesnive juggernaut roster construction that emerged during this time period became the template for the Penguins organization for decades.