I would buy animals that you like! If you find a reduce patterned normal and a nice reduced fire and you like them both, go for it! Breed what you want to breed for!

For example: I have a nice reduced pattern normal myself. Next season, she's got a date with my reduced lesser in the hopes to make some cleaner lessers! But then again, I like reduced lessers. Now, I like busy black pastels, so if I were to ever get a black pastel, I'd want it busy and I'd probably breed it to a busy girl.