If it is granite, you will only make dust with a hammer - you are right.
I use a Darda 12 - it is air over hydraulic.
The thing about the splitters is that they are the perfect compliment to a hammer because they actually work BETTER in harder rock. Conversely - the hammer works better in softer rock, where the splitter only breaks small pieces and you get very low yield for each drill hole. The harder the rock, the bigger the chunk you will break off with the splitter.
You really must know what to do though - you must face it the right way, and always elevate the tool off the rock.....or you'll be sorry.
I would probably use both - start with the hammer up top where the rock is oxydized, then use the splitter as you get into the hard stuff.
We deal with this stuff every day in Southern New England - I get a good laugh when I drive by a Cat 345 with a 10,000 pound hammer in the SAME spot every day for a month - making SMOKE.:lmao
You just know the GC is getting screwed, or he is stupid.