I have approximately 15 number fields in a field group. The user will only be entering small values, the most being 150. I don’t need the fields to stretch the whole width of the metabox, and it would be nice if I could organize them to be display side by side, instead of stacked. Is there a way to accomplish this?
The latest version of acf provides the feature that you were looking for.
You can specify the percentage of space horizontally that you want a field to take.