In Boston, KG averaged between 18.8 and 14.3 ppg as the third option. There's no doubt that if he was ever asked to score more points he could have. Not 30 but 20 for sure. Horford, with the Celtics has averaged 14.0 and 12.9 ppg with a lot of the offense running through him.
Horford averaging 18 ppg in this playoffs has been great. But he's still not as aggressive of a scorer as KG was.
I do have doubts about that, actually. I remember clearly that KG was reluctant to be a go-to scoring option, didn't want to carry that load. Preferred to be a complementary offensive player and focus his energies on being a leader on defense.
Even when he was the top scorer for the team, during the 2012 playoffs, he scored fewer than 20 points per game.
We can quibble over what "carry the team on offense" means, but scoring in the mid to high teens is not that, in my mind.
It's true that KG was capable of being a lead scoring option earlier in his career, but that's not who he was in Boston. Particularly not after the 07-08 season.
Yet I think we would all agree he was 100% worth whatever the Celts had to pay him to play for them during the 09 season (when he was healthy) and in 2010, 2011, and 2012. He was the heart and soul of that team and he was clutch on offense when he needed to be, even if he wasn't a guy who could "carry the team" on that end.
Horford, I submit, is similar to that version of KG in a lot of ways. If there's a gap in how "aggressive" the offense is between this version of Horford and 09-12 KG, I think it has more to do with how the Celts' offense is constructed than with any lack of determination or grit on Al's part.