Hey hey,
Each of those consumers, use consumer testing tools native mock capabilities, and then converts successful matches to Pact specification format files.
If you already have a consumer generating consumer pact files via a Pact client library framework, this is the ideal scenario.
You can indeed use BDCT to compare that consumer pact file with the OAS of your provider.
Are you currently doing provider verification with a Pact client library, for for provider?
BDCT will not utilise provider states, or matchers so that is one caveat to be aware of, but these won't stop you from doing the pact -> oas comparison