@Branwen84 I was just about to open my game and look at the computer Adoption to get an image for you but if it's working for you now that's great. One word of warning though about the computer Adoption, I'd save your game before starting the process just incase the pet carrier gets stuck in your home. It's huge and I had one blocking an apartment door once that couldn't be deleted. Luckily I'd just saved so I could exit without saving and try again.
The pets may have a little scrap at feeding time whether it's mixed or 2 cats and 2 dogs. It helps to space out the bowls. I don't find they fight excessively and I often have more than one. But if a pet has the Aggressive or Territorial personality trait I often keep them solo and train them well before mixing, they do often go for Sims ankles too if they have those traits but you can train it out of them. My pet rescues have max household pets and also have many visiting strays to the feeding, toys and sleeping areas and they don't fight much amongst each other or with household pets. They just don't like to eat close together in my game.
When they do fight, you'll see a cloud of dust around them. Click on it to stop the fight, then click the animals and choose "Lecture about attacking". After several lectures they should stop and you should get a notification saying for example "Fluffy has learned not to attack". Lecturing can impact your relationship a little so if you make a fuss of them afterwards it stops the relationship suffering.
