in the interium I was going to have a number of buildings that the current buildings in Subdue Animals require to be built. However, I have asked Afforess for an OR option on the prereq buildings so that, for example, lion cage could require either the menagerie or the carnival building and the menagerie requires either the Palace or Forbidden Palace. Which will make life easier for this mod.
After getting a response to my question, which was basically the same as yours, on the WoC forum. I did it the old fashion way. I created a whole new set of the animals except I called then SUBDUED_animal_name, they have bAnimal=0. Then in the python I will check the animal caught and replace it with a subdued one.
Are these the ones that come with your Subdue Animals mod? Otherwise I am going to have to go hunting
I don't have the graphics, so I am using the monster ones ATM. However I have saltwater crocodiles, small and large, working and hope to have sharks and whales done soonish. What can I say, I live in Australia and these are the ones we have

. Even if in some years more people get killed by elephants than sharks, like 2008. I am keeping the kraken unit but only for aesthetic reasons, they should never be met by any ship as I have restricted them to oceans.
The
Exotic Animal mod adds horses, camels, elephants and stag. I will also be adding my locust units you will not be capture them.