Newsflash: Would you allow the sellers agent to also represent you as a buyer?

Good day all. I have found a home on my own without a broker. The seller’s broker (who is the listening agent so there’s no one else involved in the sale) is requesting that I sign an exclusive right for them to be my broker as the buyer. I assume this is an attempt just to collect full commission (agreement states I will pay a 3% commission so I assume the seller is also paying 3% for a total of 6%). Correct me if wrong, but I see no way how this helps me in the negotiation of price, terms, etc. as the brokers incentive is still to sell the house at top dollar, not negotiated better deal for me.I do realize that when all is said and done, commissions are paid out of the final sale price of the house but just wondering how much animosity I would create if I stated I will not sign these documents and if I am providing a disservice to myself. To clarify I have hired a law firm in the state I am purchasing to represent me, so needing a broker to help with documentation, procedure, etc. is not necessary. Thank you.