Smaller capacity batteries are usually only at a disadvantage in outdoor settings, on tracks over 120-130ft in length.

If you are indoors on American style tracks, the smaller batteries are usually good enough to be competitive. A little more corner speed at the expense of a tiny less punch.

Both methods can win races, I would say run what gives you the best lap-times and consistency over the length of your race. The clock won’t lie. For some, that will be a bigger battery, for some, it will be smaller ones.