Most sellers need to realize that their home is pretty much cookie cutter.
Personally, I think most sellers won’t play nor their agents. If you look at the agent offer forms, they are really about protecting the agent, their brokerage and their commission commitment. They aren’t about protecting the buyer or investor.
If three homes are similar enough that you like them all and they are the basically the same, same neighborhood, same floorplan, etc.
Lowball one. The price you want to pay minus 10-20%. If they don’t negotiate, move on. If they counter, counter back, if you think you can get to the price you want. If not, move on to property two after a week or so. Repeat. Move on to property three. Let them sit a couple months, meanwhile, find three more homes you like, repeat. If still no sale, if move one or go back to property one now that they’ve had a chance to make another three or four monthly payments and had a couple looky-loos breeze through, submit your original offer minus 9-12% (the current monthly fall rate of sold homes.) They’ll probably brush you off, move on, repeat.