Cavani and Neymar were not on the best of terms last season, the latter repeatedly clashing with his Uruguayan team-mate over spot-kick duties as the Brazilian superstar sought to boost his goal tally.
The pair have settled their differences since and helped Ligue 1 champions PSG maintain their perfect start to the season midweek – Cavani scoring twice while Neymar was also on target.
Asked about Neymar and Cavani appearing closer than last season and whether it was thanks to him, Tuchel said: "You have to ask them! Great players have to play and live together, it's very important.
"I feel that Ney, Edi [Cavani], Angel [Di Maria] and Kylian [Mbappe] form a group that wants to win and improve together. I'll always tell them that's what I want."
PSG made it seven successive wins to open their title defence but the holders conceded first against struggling visitors Reims, who opened the scoring after just two minutes via Xavier Chevalerin.
Cavani responded three minutes later and netted PSG's third on the stroke of half-time following Neymar's 24th-minute penalty that put the hosts ahead.
Thomas Meunier came off the bench and sealed the rout 10 minutes into the second half, much to the delight of Tuchel as PSG restored their eight-point lead atop the table.
"I am very satisfied with the first 60 minutes, we played fast and easy, with very few keys," the German boss said. "We recovered the ball very quickly. We did that for 60 minutes."
On the record start to the season, Tuchel added: "We are very happy to beat this record. It was a goal. This lays the foundation for continuing to work well."