Vella has played some outstanding games for us. He lackjs consistency, and he is a forward leader - therefore consistency is required.
Wagon is a tackler, and played very well last night - neat kick on the first. However, he has gone MIA as well. If you have a potential backrow of Morrison, Cayless and Hindmarsh, with Afasamaga on the bench to cover (and with possibly 2 props and Thporman to cover hoolker/half), where do you find room for a mere tacklaholic? Morrison, Afasamaga Cayless and Hindmarsh offer so much more than that.
Wags can cover a hell of a lot of bases. Centre, where we may still be thin, 5/8 (when we are desperate) and back row. He'll be an excellent utility, but not in the run on side at full strength.