As long as there's 1 installment loan reporting a low % balance for both of you. The other 2 really dont do much for scores. But does help with payment history.
I agree that credit mix will not be significantly effected by paying one of multiple installment loans.
Additionally, installment loans are not included in % util of revolving, and current loan balance is not a major scoring consideration.
More significant is the the payment history scoring of the prior COs.
Paying permits the scoring of the derogs to age in impact, but does not remove them.
Did you attempt a pay for deletion when you paid those delinquent debts?
You might wish to pursue good-will attempts to get those major payment history derogs removed. That would be significant.....