No that API doesn’t support it.
You’d have to do one request per streamer you want the follow count for.
https://api.twitch.tv/helix/users/follows?to_id=CasterID&first=1
Alternatively, get the follow count periodically (say daily), the use the follows web hook to count up in real time. Which would reduce your API count to once per day per streamer. (Since the hook doesn’t send unfollows)