Celebrim
Legend
TBH, if I were going to include STR racial caps for halflings it would be much lower than 17. These creatures are 3 feet tall, thats under a metre. The difference between the brute STR of Humans and Halflings or even Half-Orcs and Halflings should be massive.
If you assume that halflings are built to the same body plan as humans, then yes, you are correct. They probably only weigh 30 pounds, and that severely limits maximum strength. You might assume that halflings are no more strong than toddlers.
However, humans are built along one of the lowest strength to mass ratios of any animal their size - built for caloric efficiency and endurance, not power. A typical 80 pound female chimpanzee is stronger than a typical 200lb male human. Supposing that halflings are built along the same body plan as chimpanzees, with relatively thicker bones and larger attachment points for muscles, and more fast muscle and less slow muscle gets us a very different answer. Such a body plan might also explain why halflings are afraid of water in the source material - they don't have near neutral buoyancy the way humans do, and instead sink like rocks. It also explains why halflings would be so athletic for their size.