Do exactly what Odoo does when proposing reconciliations. This searches for an exact match on amount and reference first, but falls back to less exact matches if none are found before. If there's only one match, do the reconciliation
Exact amount and reference
Strictly only match if we have the same partner, amount and reference
Strictly only match if we have the same partner, amount and reference. Check at least one field one the statement and one field on the move lines to tell the rule which fields to match with each other.