The important thing to bear in mind is that Sun organizes their exams (and consequently, their prerequisites) based on "job role". As far as Sun is concerned, the architect role is entirely separate from the programmer/developer role (hence why SCEA has no prerequisite, as opposed to all of the upper-level developer exams).
I don't know that it's necessarily realistic - I don't know that, as an SCEA myself and a manager, I'd hire an architect who has no experience with development - but it's certainly understandable where Sun's coming from on this.
Theodore Jonathan Casser
SCJP/SCSNI/SCBCD/SCWCD/SCDJWS/SCMAD/SCEA/MCTS/MCPD... and so many more letters than you can shake a stick at!