Since the ramp sets usually include the "warm-ups", that should be all right.
It's different with Wendler 5/3/1 or ramped 5*5, though. There, ramp sets use small jumps of 5-10 percent of 1RM and you get actual warm-ups before those sets.
If you were to use the 100's (hypothetically) for DB incline presses for 4 ramp sets (standard BB style), that'd mean starting with the 30's or 40's for, say 12 reps, then the 55-60's for 8, then the 80's for 4 or so, then the 100's for as many as you get...
Now if you only use, say, the 60's, just don't do as many sets then or do smaller jumps but lower reps on the warm-ups to keep fresh for you top set...
20*12, 40*6, 60*AMAP
Or whatever else you prefer... You can go with the smaller increases but more sets, of course, though in that case I'd go 8, 5, 3 on warm-ups (or so) to save energy.
Many ways to go about this, others like keeping reps the same on every set.
And hey, the stronger you get the bigger the jumps on ramp sets will become (to the point where you'll need more than 4 total sets on exercises like squats and deadlifts and such).