I know what's wrong and they won't accept my changes

Marking up a contract is one skill; getting the mark-ups accepted is another. Commercial teams reject amendments by default, because most they see are asked for without authority and giving nothing away usually works. What moves them is knowing which of your asks are industry standard, which of their clauses would not survive the Act, and what they can actually trade.

That is a negotiation discipline, not a drafting one. Run properly it protects the relationship: the argument stays about the document and the industry's standard positions, not the people, and you start the job with terms you can live with rather than resentment carried to the final account.