What is the argument against the ICOC doctrine of "Disciples Baptism"? The International Church of Christ, as I understand, teach the idea of "Disciples Baptism", which is distinct from both "Believer's Baptism" and "Infant Baptism".  It teaches that people who are just believers can not be baptized, but only believers who have attained to a certain level of discipleship where they can be considered disciples.

What, is the argument against this specific teaching?
There are two main arguments against it. 


One argument is that it is fairly arbitrary to decide how far advanced in
discipleship someone needs to be in order to be baptized. Whatever
level you set, there will be some who never attain that level of
discipleship - however normal Christian doctrine would say that
those people are nonetheless true Christians and members of the
church. Likewise some may attain that level of discipleship and then
fall from it.
The main argument however is that the Bible is full of examples of people
who were baptized as soon as they were converted. Acts 2, Philip and
the Ethiopian in Act 8, and a whole host more.