This is a bit of a straw man question. It's founded on the statement "the Christadelphian view that Satan is not a person" backed up by repeating the text of another question from a non-christadelphian as fact... and not the answers to that question from Christadelphians themselves.
Many satans (adversaries) not one
I am Christadelphian, and I'm not going to repeat the answers to the linked question here, except to answer the more specific question about the satan in Job. I think it's more accurate to say the Christadelphian view that Satan is not a single person. We don't believe there is a being that has existed from the time of the garden of Eden until now, that is referred to as "Satan" i.e. the Satan. The original idea of the Hebrew word is "an adversary" or "to be avesarial", and so in that sense we would say there have been many adversaries to many people throughout history.
Peter was an adversary to Christ in the moment he tried to stop him going up to Jerusalem. Moments before this incident, Christ praised Peter for his faith. To be a satan (adversary) to someone can be a mild single point in time verbal objection not understanding the consequences (as in Peter's case), or a more long term stronger ongoing physical persecution. Context is key in interpreting scripture.
Who is Job's adversary?
The question of who the satan (adversary) to Job was in that moment is an open question within the Christadelphian community. You will hear many suggestions varying from and angel of Yahweh, a jealous israelite, to Elihu, and many other things in between. The simple fact is we just don't know for sure, I don't personally have a strong view on the identity of the adversary.
Our general approach in these situations is that if it was really important that we knew exactly who the satan was to Job, then we would have been told... or it would be obvious to work out. Having said that it's this kind of thing that Christadelphians love to argue about (I mean "discuss"). There is a risk here to over emphasis small details (arguing over the exact identity of the adversary) and miss the bigger picture of the message God is trying to convey to us. The old adage, "strain at a Gnat and swallow a Camel" is perhaps an appropriate phrase. I think the focus in scripture seems to be more on Jobs response to the persecution, and his three well intentioned but misguided friends, than the satan that was used as a tool to start it off.
Personally I would say it's the same with what happened in the garden and the satan (adversary there). Our response to fallen nature and the trials of life is surely more important than the exact nature of serpent who was (I believe) an unwitting adversary to Adam and Eve, used by God to bring us into a situation where we have to use our free will to demonstrate love and obedience to God in our lives. We can blame others for our actions (as Adam and Eve did) or we can take responsibility for our failings and do our best to develop God's character in us as his sons and daughters... part of his family.