Parksider A lot of people mix in the seasoning either before they grind or between the first and second grind. If I didn’t have a mixer, and I was making a cured product where I needed protein extraction, I might add the seasoning after the first grind and then grind it again. I don’t do it this way with a cured product because it is usually a while until I can get to cleanup and seasoned meat seems to be harder to clean than unseasoned. I wouldn’t do this if making a fresh product as I’d worry about the protein extraction starting too soon but that is probably me just being overly careful.
Mixing the water in with the seasoning before the meat is fine and plenty of people do it. In the end, it really shouldn’t make any difference as long as you mix the meat enough once it is all added. However, I always tell people if they have found something that works for them don’t change! If that process works for you (and considering the sized batches you do who could argue with it?) then stick with it!