How Extracting address Bitcoin to script multi signature
The correct address is 3CD1QW6fjgTwKq3Pj97nty28WZAVkziNom. The individual public keys are only able to access the coins if they act together in a group of at least 2 out of 3. If you derive a regular p2pkh from each individual key, you will end up searching for utxos that likely don't exist.

Also note that each individual public key does not necessarily mean that there are that many individual people involved. Many security conscious companies and people have multisig addresses with each key stored on a separate device/location, requiring multiple signatures from different systems, etc. They may all still be under the control of a single entity.

When cataloging transactions and matching patterns across the network, you should be working with the P2SH address for a multisig address. Breaking it down into its components will produce incorrect results.