They need to start the Turtles universe with a Punk Frogs movie.
Imagine punk Frogs has splinter training them, some disagreement then they leave. Then do TMNT, normal story, splinter dies. Then a punk Frogs v TMNT, at the end have Napoleon jump on Leonardo and Leonard says Splinter... And Napoleon is like did you say Splinter, why did you say that name! Then they team up and fight the real enemy, Baxter Stockman played by Jesse Eisenberg.
Shame the Punk Frogs didn’t show up much after the original series. I think the 2012 series, I recall there was a cameo by Napoleon , looking it up now... voiced by Jon Heder (Yup, Napoleon Dynamite). Lol.