Send the same request to every provider
Ask for the original signal record, not a selected dashboard image. The record should include publish time, intended entry, invalidation, exit rule, revisions and skipped or cancelled calls. Request a definition of what counts as a filled trade and a win. These details make a fair comparison possible even when providers trade different instruments.
Classify missing evidence honestly
A provider may decline to share proprietary rules while still publishing an independently checkable outcome record. Conversely, a long methodology page cannot substitute for a timestamped trade population. Mark each row as supplied, partial, unavailable or not applicable, and preserve the reason. Do not turn absence of evidence into an invented low return.
Make the commercial decision separately
Once evidence is sufficient, compare access windows, support, risk disclosures and subscription terms. A verifiable record does not mean the signals fit your broker, time zone or risk budget. Run an executable trial using your own fills before committing to a long plan.