If you think about it. Shimo wasn't ever really Godzilla's enemy. She was afraid of being tortured if she didn't obey Skar King so she did his bidding. Once she was freed she was more than happy to say f you to her captor and gave him the deep freeze special.

I will say this Hobbs is a bigger threat than Torreto however Torreto has more of a reason for wanting Reyes dead and gone so who knows Dwayne and Vin might have to put there rivalry aside to let both characters team up and take down Reyes