I think that’s a good assessment.
As for my approach, I would maybe do it something like the following:
First, I would draw a 3D blank to start. The problem many folks have is they start thinking only in 2D and they wind up creating trouble when they go 3D. So here I’ve made the blank match the thickness of the back wall of the basins. Then I drew the curve profile for the inside of the basin. I drew the Bezier curve on the far left with Fredo6’s Bezier Spline tool and added straight edge segments for the depth of the trough and half it’s width. That gives half the single basin profile. The curve and the straight lines were copy/rotated about the basin’s center line to make the opposite half. I used Offset to create the bottom profile of the basin. Then I copied the inner and outer profiles over to the right and finished completing the profile of the sink basins and counter top with some additional straight edges made with the Line tool.
Push/Pull gets rid of the waste at the bottom…
…and extrudes the basins to half their front to back depth (or is it back to front?)
Around to the back, a straight line defins the thickness of the countertop.
Push/Pull pulls that out to make the counter top surface behind the sink. Underneat there’ll be a few coplanar edges to delete. Do them next to keep your model clean.
Then select all of the geometry and use Move/Copy to make a copy the back half of the sink out in front of the original. While the copy is still selected, right click on it and choose Flip Along>Green Direction to mirror the geometry creating the front half of the sink. Move the copy into place with the back half and erase the seam lines. After you’ve placed the copied and flipped geometry in place, you can go to an end view or the top view, drag a selection box around the seam lines and hit Delete. If you moved it correctly, you should still have all of the faces. Pull out the front edge of the counter top to make the top face the right width and add the front face by drawing a line across the underside and then using Push/Pull to pull it down.
At this point I made the sink a component and checked to make sure Entity Info reported it as solid. If you get to this point and it isn’t solid, take a few minutes to clean up. Thom Thom’s Solid Inspector can be a huge help here.
I noticed in your model you added the slopes in the troughs so water would run to the drain. This detail is probably not critical to show unless this is going to be used for manufacturing the wink. If you need to add the slopes, draw lines across the trough where the drain holes go and move them down as needed. Move the edge at the front of the trough up to create the slope down to the back.
To cut the holes for the drains, I created a cylinder component making sure it is also solid. then I used Eneroth Subtract from Eneroth Solid Tools to make the openings.
When you get all finished, you should have a sink component and it should still be a solid. In my short time of using SketchUp, I’ve found that solid components are always the cleanest and easiest to work with and I shoot for making every component show as solid in Entity Info.
And for what it’s worth, even after erasing a bunch of geometry in your sink, you can see the entity count is pretty high compared to mine…
I’m guessing mine would have adequate detail to communicate what needs communicating.