The problem with three systems is that each one slowly ends up holding its own version of the procedure, and nobody is fully sure which one is current. The fix is to pick one system as the source of truth for the approved procedure and have the others pull from it instead of keeping their own copies.
For most sites, document control stays the system of record for approvals, and the field app should always show the latest approved revision so operators never run an outdated version by accident. SharePoint can keep working as the place people browse and reference documents, as long as it points back to the same approved version rather than storing a separate one.