Those are all good ideas. It would also be cool if each animal could give some kind of bonus to a Ranger/Beastmaster. That would give animals more than one use. The player could choose between escoring the animal back to a city to add to the carnival or attaching it to a Ranger for a bonus. It would be made even more cool if the models for the animals would form new models for the ranger when they are attached. Each Ranger could only have one animal type attached (making for specialization) and the animal would appear as part of the unit (a lion or gorila along side the man). Wolf promotion could grant marksman and a withdrawal chance. Lion promotion could grant +1 sight range. Bear promotion could grant a +2 strength. Gorila promotion could add first strikes (or maybe make unit immune to first strikes instead). Elephant promotion could add colateral damage. Tiger promotion could give +1 movement and multiple attacks per turn (like blitz). These are just some ideas. I'm sure that others could come up with better ideas or at least more balanced ideas.