Wow. You are getting all sorts of input. Some on target, and some of it irrelevant. And some of it plain misleading.
Actually, no one can answer your question without seeing the Listing agent's agreement with the Seller. It is possible that in your circumstance the agreement could stipulate that a portion, or all, of the amount to be offered to a Buyer's agent could be deducted from the commission promised to the Listing agent.
Or, the agreement may not even address a circumstance like yours.
No one knows how the agreement was negotiiated from the information you present, but as noted, commissions are negotiable.
Consider a few points:
1. Even if you use an attorney, how will you access the property for inspections, appraisals, contractor estimates for repairs? Would you depend on the Listing agent for that?
2.. Should the Listing agent do that for free, or would you expect the agent to receive compensation from funds designated for a Buyer's agent for doing those tasks?
3. Would the net proceeds amount to a Seller be increased if the compensation was reduced, or would you expect to benefit from that, as a buyer?
4. If your attorney draws up a non-standard form, and the Seller must have attorney review of the Offer, would you expect that cost to come from the Seller's net? Or would some of the commission dollar designated to be offered tor a Buyer's agent reasonably be earmarked for that expense?