If a horse is hetero Lp with pattern 1, they'll be leopard regardless of pattern 2. If homo Lp with pattern 1, they'll be snowcap or fewspot, regardless of pattern 2.
So because he had one pattern for both 1 and 2 he could be multiple kinds of Appaloosa if you reroll him, not just one that you'd get from 1 or 2. He could even get varnish with others because of having both.
So starting with Leopard complex its just saying whether it'll be an Appaloosa or not. The patterns determine what kind and it can be an Appaloosa without a pattern as well.
The Brindle part just tells you if it's Brindle positive
The phenotypes are things that are random and not breedable