It's generally recommended to put marbles in the waterers base 'so the chicks don't drown'.. I, personally, have never used marbles or stones in my waterer and I've never had a drowned chick.

Out of Pure curiosity, how many do or don't do this?
I've done it both ways. I've never had much trouble with drowned chicks (just a few, over many years and hundreds of chicks.) The chicks that did drown were in batches that did not have marbles in the water.
I've decided I do prefer to put marbles in the waterer for the first few days, for an entirely different reason: the chicks peck at the marbles and get water in their beaks, so this teaches them how to drink. Once I decided that worked, I completely stopped dipping beaks on newly-shipped or newly-hatched chicks. I remove the marbles after a few days, because it is such a nuisance to dump & refill the water with marbles in it. I might leave just a few marbles for a day or two past the point when I take out most of them, but they are all out sometime between day 2 and about day 5, depending on my patience level at the time.
As regards teaching chicks to drink, I think it is more important to do something when there are just a few chicks. The more chicks in the group, the more likely that some will figure it out anyway. Once a few have learned how to drink, the rest copy them and learn too, no matter how many or few chicks are in the group. I think the marbles work better than dipping beaks, with less stress for the chicks and for me.
Oh, I just remembered another detail: I have always used the little chick waterers, that screw onto a jar, when starting young chicks. I may switch them to a bigger waterer when they are a few weeks old, or not, depending on how many chicks there are. But the little plastic chick waterers are already a pretty good protection from drowning. If you had to water chicks from a big open bowl, they might be more likely to fall in and get wet, chilled, possibly drowned. That could make marbles or stones more valuable in that situation.