Honestly a lot of the rivals are not that great in my opinion a lot of them don't make since to me. Like Fat princess and Evil Cole, Kratos and Sweet Tooth, Radec and Sir Dan, Dante and Nariko, Good Cole and Raiden. It's not a big deal but I feel like a lot of the rivals aren't great choices.
Kratos and Sweet Tooth - both created by David Jaffe and are mass-murderers
Radec and Sir Dan - soldiers
Dante and Nariko - both developed by Ninja Theory
Cole and Raiden - Raiden is Japanese for lightning, and what are Cole's powers again?
Those all make sense to me, although the Radec/Dan one is a slight stretch I'd say