Yes and no... there are still only two chompers, but their "preferences" can be used in a variety of combinations. In essence the red chomper will go after (in decreasing order of preference) Stinky, Loof, Qookie, and Peegue, whereas the yellow chomper will follow Loof, Qookie, Peegue, then Stinky.
(you also asked a few things in PM... I'll answer them here since others might have the same question)
3D Models: don't have to be houses, can be anything. So yes, you could make an airplane and put it in the level. Just note that it is a static object, not flying around. But you could make a "Stinky and Loof visit the Aircraft Hanger in Area 51" level.
# of gates, teleporters, etc. Yes, they are limited for basically the reasons you guessed - but more precisely it is because the number of clearly distinguishable colours is limited (esp. for the gates, which are "see-through"). I looked for a long time to find an eighth gate colour that wouldn't look almost like one of the other seven in a level, but couldn't find one - hence "only" seven coloured gates.
Oh, and I guess this post does contain one new piece of information for y'all, doesn't it?
