Many agents will make part of their marketing how they battle for you. This may end up being a determent however. While our fiduciary responsibility to a client does insist we as your agent work on your behalf and hold your interests at heart. Sometimes the biggest way to get what you want (your interest) is to flex and negotiate and find a win-win situation.
The win-win concept is a big part of why I chose Keller Williams as the brokerage I operate out of. The Keller Williams Belief System is extremely easy for me to get behind. It's summed up like this:
WI4C2TS
Which stands for:
Win-Win: or no deal
Integrity: do the right thing
Customers: always come first
Commitment: in all things
Communication: seek first to understand
Creativity: ideas before results
Teamwork: together everyone achieves more
Trust: starts with honesty
Success: results through people
Over 90% of all residential real estate transactions in the Kansas City Market have two agents. One representing the buyer and one representing the seller. If all of these agents were "battling" for their sides they'd be considered adversarial agents. However, how they're seen in practice and name by the National Association of Realtors is COOPERATING agents.
It's very possible to work for your client and be cordial with the cooperating agent. I've found the transactions with the best outcomes for all parties are the ones where the agents and buyer and seller are able to find common ground and ensure a win-win situation. It's difficult to find a negotiating hurdle that can't be overcome in a real estate transaction.
Typically the number one dispute is price. Each agent should be skilled in researching comparative sales and coming up with a ball park market value. Once presented to their clients and talked about an offer can be presented or countered and those comparable sales that determined the offer or counter offer price can be shared.
Maybe the dispute is over a washer/dryer or awesome refrigerator. Perhaps it's something as simple as a home warranty. There have been times that I've split the cost of a home warranty with the cooperating agent. I've also helped sellers make repairs to ensure a transaction could happen. This benefits all parties in all situations. The only reason (I can think of) that people are unwilling to do this is pride or stubbornness. Battling for their clients. Blowing up a deal on the perfect house because the buyer and seller couldn't agree on a $600 home warranty isn't working in anyone's interest.