Hey Fibro,
This is just my 2 cents.
You are one of the posters here that I really respect in relation to your football knowledge, I know you that you probably know a sh*tload more about footy than I do, but based on the games that I have watched (and I have only missed 3 this season) Aiton has been disappointing.
The ruck defense falls apart when he is on, the timing of his service out of dummy half is poor and not fluid (thus forward passes) as he can't decide whether to pass or run, he has no kicking game whatsoever and I truly believe that his only strength (his running game) has diminished in the past 2 years as teams know it's the only thing he can do, at one point every time he ran the ball he was getting smashed.
Fair enough ME doesn't give him much time, but hell most young hookers start off only playing 20 or so minutes off the bench. The key is that the good young players develop their game and they show enough during this time to warrant releasing the older veteran to give them the full time job (e.g. Ballin, Keating, etc). The reality is that Aiton was great 2 years ago when his running game was top notch, however he has regressed since and has not developed sufficiently to warrant letting him stand in the way of Iosefa. Now whether Peters is better than Aiton I don't know, but I saw no drop off with Peters there last week, I would prefer to have Iosefa start and Aiton on the bench as his running game can create a spark.