I think Marco would def fight tooth and nail to get outta the Red that his dad got put into after his mom died. And can you imagine David as a cronie of the evil dude, Sushin? And Taylor would totally be an Ice Carl too, she'd just be a different tribe than Rachel and Cassie, and they def wouldn't get along. Where would Jake and Tobias be? I think Jake would be Orange, it seems like mostly middle class, which is what his family appeared in canon. Tobias might be a servent?
I think the key with a crossover with Animorphs is to work in either literal Yeerks or Yeerks as a good in-world stand-in. (Like the Visser in Pottermorphs, or demons in Supermorphs.)
And the kids themselves do probably have to be in the same group because you will pry Rachel and Jake being cousins and Jake and Marco being besties forever out of my cold, dead hands. And Marco being demoted to red is too perfect so, damnit they're all Chosen except Tobias who totally is Underfolk. I agree about Jake and his family being Orange. Naomi totally clawed her and her girls up to Green though. Cassie is probably Yellow, though I have no idea how to work animals into her life there. Maybe she's a pro beastmaster player? She and Marco are probably playing a LOT. (Jake is terrible at it.)
IMAGINE DAVID AS THIS SMUG LIL BLUE ORDER KID THO, LORDING IT OVER THE REST OF THEM, MAKING THEM SHOW HIM LIGHT IN RESPECT. i just like snotty spoilt david okay.
what if elfangor passes and gives the kids the morphing ability JUST AS the yeerks make their final move in taking over the entire castle?? the kids have to flee, and they end up with the icecarls, trying desperately to A. not die and B. convince them to join forces and attack the castle before the yeerks take them over too. imagine the wicked ice monster morphs they could get
IMAGINE THEM FINDING AX, A PRISONER OF THE CRONES, WHO IS V HORRIFIED AT THIS SPECIES
imagine them going to aenir
IMAGINE IF THEY COULD ACQUIRE CREATURES IN AENIR THO AND CARRY THAT OVER TO THE REAL WORLD