Paint the Night does not have 18 floats. Counting distinct motorized floats with their own driver, there are 12-13 floats, creating 8 units. Some of the floats have multiple parts linked together, but ultimately those are only counted as a single vehicle (such as the literal tractor-trailer, Mack):
2-3 rolling puppets also followed the Tinkerbell; these puppets were originally used for the short-lived World of Color pre-show and were mounted on rolling bases for the parade, and are manually pushed along the parade route. The DCA run of the parade also added a UFO with aliens to the Toy Story unit; this was originally in the daytime Pixar Play Parade and appeared to be manually pushed from within during PPP, but motorized after its PTN overhaul.
- Tinkerbell (w/ Drum)
- Monsters Inc.
- Lightning McQueen
- Mack (cab & trailer)
- Little Mermaid
- Toy Story Slinky Dog
- Toy Story Aliens (added for DCA run)
- Belle (w/ 3 chandeliers, Rapunzel, & Cinderella)
- Frozen (DL) or Incredibles (DCA)
- Ball w/ Goofy
- Ball w/ Donald
- Ball w/ Minnie
- Mickey Finale
While 12ish floats is on the longer side of Disney's modern parades, it pales in comparison to the peak of the nighttime parades which often had 30+ floats. Sure, these ones are a lot more technologically advanced, but in terms of sheer scale PTN comes up short; even in person, it leaves most people wanting more. Unfortunately, I see no reason to think that MK’s new parade wouldn’t follow along in a similar scale.
Well, when MSEP had it's own VHS Souvenir video, Cinderella who is the hostess of the video (Played by a cast member) says that MSEP has over 41 floats. But this is before MSEP started to cut some of the of the floats, like Dumbo.