I see what you mean, but it works more like this, so that can't actually happen:
Round 1
A Posts Attack
B (Monsters Attack), round resolves.
========
Round 2
C Posts Attacks
A Posts Attacks
B Monsters Attacks, round resolves.
Sure, fast posters that are in group A might post their attacks first, but group C actually GOES FIRST in round 2.
It's just a way of keeping the "monsters go" at the end of the round, when the DM resolves all actions.
Rogue 19
Ranger 16
Monster 12
Wizard 7
Cleric 4
-repeat-
is exactly the same as
Rogue 19
Ranger16
Monster 12
THEN
Wizard 7
Cleric 4
Rogue 19
Ranger 16
Monster 12
You see what I mean?
That said, I only pay attention to the actual initiative rolls when there's a conflict, which RARELY happens.
You'd be surprised how rare it really matters who did what first.
I've run, what, six fights this way so far, and I've yet to see it really matter. In particular when you do what Aurewraith and I are doing, which is to send "overkill" damage to the next logical target, which is one of the only places where it's an issue.
Anyhow, I'm not trying to convince Az to do it that way, I'm sure you've got it under control!