Admittedly, Demore Barnes’ Garland actually would have made the most sense as a go-between for SVU and Organized Crime due to his spot higher up the NYPD ladder, and I’d once held out hope that Kat would actually transfer over to Organized Crime because she seemed like she could be a good fit for Christopher Meloni’s show, but there is some precedent for the two shows sharing characters.
Honestly, Mariska Hargitay practically recurred on Organized Crime Season 1, and will appear in the spinoff more in Season 2.
Carisi had a part to play over on Organized Crime last season, even though Peter Scanavino was still very much a series regular on SVU.