to clarify what my relationship would be to these folks - I aggressively market my design and project management services to homeowners in my area. So these design-build companies aren't looking to sub that to me; what they want is for me to do the work of acquiring my client, taking them all the way through the design process, and turn the client over to them in exchange for a couple hundred bucks "finder's fee." It's an awesome deal for them. And because they have their own staff designer(s), I get precisely zero referrals coming the other way. So I come into these conversations extremely skeptical and maybe (on a bad day) extremely blunt.
For lawncare companies, I feel like a stock photo of green grass is fine until you can get some nice shots of your own work. But it's cut grass. That's way different from a gunite pool with a flagstone deck and crazy waterfalls spilling into it that you're passing off as your own