I would recommend not using abomasnow unless mega evolving, and celesteela is not ideal. However, I understand if u have put lots of effort into training them and find them quite powerful.
Ninjask would be a good 6th pokemon. I always use it until I find something better, as it is very useful.
Very good move sets :) except for ingrain, which is probably best substituted for a move like rock slide to compliment abomasnows weakness to fire and flying. with an abomasnow that is relaxed or something that promotes def, then feel free to use ingrain
Only suggestions