I had a look at my own results out of curiosity, and my _total is also 2 higher than the number of items in the follows array. It says I’m following 102, but I’m only getting 100 results back (and yes, I am checking once with a limit of 100, and again with an offset of 100).
After testing using a limit of 1, it’s specifically at an offset of 95, and again at 100, that I receive {"_total":102,"follows":[]}. So _total seems to be including those 2 empty values in its count. As to what caused those empty values I’m not sure of, only thing that comes to mind might be an account being deleted/banned and for those following that account to still be following it, but as the account would not contain a bio, logo, status etc… the follows API wouldn’t include it in the results and just continue on to the next in the list.