At present I only know of three options: unmodded (spawns 5 Large Dogs, 5 Small Dogs and 5 Cats), No Stray Respawn (which disables spawning altogether), or dickhurt's hypercomplicated "Pet Modifications", which affects way too many other things besides number of strays.

So, how would one go about modifying just the number and kind of strays? (Specifically, I would like more cats and fewer dogs.) Recommendations?

Looking at the code that nostrayrespawn overrides, it looks like the numbers of strays to generate for the pool are stored in BCON 0x1001 in group 0x7F3947A5, so I guess as a first step you could just try extracting that and changing the values to what you want. The function that uses those values to repopulate the pool is BHAV 0x1003 in the same group if you want to modify that in some way as well.

Unfortunately that doesn't work. The extracted file gets f'ed up, and SimPE thinks it's a Spore file and refuses to do squat with it.

Anyone got a better idea?

You can't open the XML file that gets extracted with SimPE directly, you have to create a new package file, right click the resource view and click "Add" and then select the files that you extracted earlier, and that will create the resource in your new file.

D'oh! Well, let's see if I got it this time.

Update: Yep, that worked. Game has some quirks, though - if you have No Stray Respawn and you empty out the Strays pool, the Strays family goes away. Then when/if you decide to let some more strays spawn, they will have a duplicate family name of whichever family you are currently playing. (You can always change the name back to Strays.)

My objection to dickhurt's Pet Modifications is that I would have to Config the **** out of it and I'm not sure I would get everything right. (It definitely conflicts with Visitor Controller and Simler's LotVisit mods - not sure how severely.)

Yeah, if you want strays to generate at all in the strays family, you shouldn't be using nostrayrespawn. It won't generate strays out of control if you don't have it, or anything, it'll just keep the pool at the numbers you set.