Few custom mob spawning questions

So I recently just watched the custom mob spawning video by Timber Forge ( https://m.youtube.com/watch?v=nZT6p5NSNXY ) and I have 2 questions 


    

  1. Can multiple custom mobs be on the same spawning pattern? (ex. 2 custom mobs with 2 different probabilities but they’re both checking for zombies)
    2. 

  2. Can the custom mob spawning be biome specific? (ex. A custom mob that checks zombie spawning but only in like a mess biome or smth)
    3.
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