Cross Validation Rules vs Related Value Sets

Finance guys have implemented Related Value Sets instead of Cross Validation Rules.

When costing details are entered on lets say Payroll Element Eligibility and when the payroll is run, does it look at the Related Value Sets to figure out if the costing combination is valid or not so that it posts invalid combinations to Suspense Account? Or do we absolutely need Cross-Validation Rules for Payroll to identify valid and invalid combinations?

As of now - Cross Validation Rules are disabled and we have only Related Value Sets and as a result whenever payroll is run, all the costing combiinations are considered as valid and passed - when the Create Accounting process is run to post transactions to General Ledger, all the invalid combinations fail.