The one thing about using tire companies sujestions, are. They dont always give you the look you want. They just know they will fit. They dont want to be responsible of a sujestion that tucks in or sticks out too much. Most of the time I see their sujestion tuck under more than you want for that wide stance. With the rim still under the fender.
I always look at offsets and rim widths. Not to concerned with backspacing. Although it is a good tool. Especialy with really wide rims. You have to know if the rim edge will rub on suspension parts.
Yes the deeper the backspace the closer inside the rim sits.
I have bought alot of custom rims. Sometimes 3 set for the same car, during its life,,$$$.
Sometimes I actually sit down and draw a pattern of oem width and offset, and a pattern of the rim Im looking at. It gives me a visual. To compare to fender clearance.
I like a street rim to be under the fender just enough to clear. It got complicated to shop for cars that I lowered..:banghead: