I am not sure though what you mean by "grass options". Grass bunkers are a weird form to me, unnatural and unnecessary. Just stop the short grass where you want it to stop, and start the rough, you don't need to dig a hole.
I grew up liking grass bunkers, probably because I saw so many grassed over former sand bunkers around Chicago, I came to think of them as an art form. Among my favorites always seemed to be Langford former sand bunkers, with their 1.5 to 1 bank slopes and wavy top edges.
And, if the slopes are right, the combo of hole and steep bank can still make it dicey to take a low enough club to reach the green, which is the same concept as often used in sand bunkers.
As to the OP, agreed mostly. 5,000 SF of sand bunker vs. 2+ acres of rough means the rough is going to statistically catch many more players. I guess that is why most gca's reserve fw sand bunkers for those critical places that may challenge the best players, although we aren't always careful about making them enough of a hazard to make them meaningful. The trend has been more towards aesthetics, IMHO.
Of course, playability, aesthetics and maintenance concerns are the legs of the so called design triangle. For most courses, the latter is a factor, another reason that "standard design practice" came to be limiting fw sand bunkers to those areas where they might really affect strategery and play.
I think Ross said it was easy to over bunker a golf course, and I have generally agreed. It's sort of like Pete Dye in the period when he used those long strip bunkers (often between a lake and fw). The first one is cool, but when you see it many more times, it gets to be a bit "meh." For that reason, for whatever fw bunkers I use, I nominally try to make each one different, maybe just one big one, a cluster of small ones, random spacing, and other different combos so each one has a chance to be visually different, another use of sand bunkers, IMHO.
Of course, that detailed answer to the OP may really just be said as, "Oh crap, did I screw up my entire career?"
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