A brief is not a prompt playground. You need one memo you can defend, without pasting the NDA into four chats.
You draft in ChatGPT. Then you paste the same brief into Claude because you do not trust one model. The merge is you, late, in a third document. A round number with no file behind it still lands in the slide.
Run Assure on this computer. Attach the notes. Use Comparison or Design. Compare & Validate sends the question to more than one model. Check against my files drops percents and dates that were not in the upload. Copy keeps the compiled prompt here if the engagement forbids a Send.
You hand the client one checked answer. You can point at the overlap view and at the file. You did not open a fourth chat to referee.
Open Compose Not installed yet
Try the example: compare AWS vs GCP for a healthcare client. Do not invent prices.