If the Orc has Powerful build then the halfling isn't as strong as them. They can make use of their strength to a similar effectiveness but a 10str orc can lift as much as a 20str halfing.
This is why I really like the Giff's Hippo Build. It makes them strong in every way except in combat. So a 10str Giff is equal to a 20str halfling in pretty much any way that matters. Honestly more races should have things like that. Like, if you want elves to be naturally dexterous giving them advantage or +1d4 or something to dex checks does way more for them than +2 dex.