Speaking Moistly
What a terrible image.
Don't think that plays out if you dig deep. Schultz's scoring that season was driven by 18 in 15 in December, and 11 in 11 in January. Letang missed 6 games in December if I count right, and Schultz was 12 in 9 with him and 6 in 6 without him; 2 in 4 with Letang in Jan, so 9 in 7 without him. So that's... 14 in 13 with Letang, 15 in 13 without him. Not really a difference. Feeling too lazy to dig deeper, but it looks like more things were in that bottle.
There's definitely fluctuation and Schultz was his most productive from about November to January but he was more productive without Letang. 0.516ppg is a 42 point player and 0.776ppg is a 64 point player over 82 games. Maybe you try and compare the longer stretches without Letang but I think there's an argument to be made that Schultz benefited from Letang being out. His playoff ppg over 22 games was better than his regular season ppg with Letang in, too. 0.619 vs 0.516.