Question about strip #484's speech balloons

[Cerlis]

http://www.giantitp.com/comics/oots0484.html

What is the correct order of speech balloons? And is there a general rule for whether vertical order takes precedence over horizontal order or vice versa?

Durkon knows the plan. He'll contact us magically--and Vaarsuvius, too--as soon as he's able.
Wait, hold on: You're saying the boat ACTUALLY left us behind?!?
Keep your voice down!

or

Wait, hold on: You're saying the boat ACTUALLY left us behind?!?
Keep your voice down! Durkon knows the plan. He'll contact us magically--and Vaarsuvius, too--as soon as he's able.

Definitely the first , there is plenty of room on the lower panel for one big balloon with the full text, so those are being said separately.
not to mention comic rules dictate that way, i believe.

whats happening in the narrative is that in the previous page (and this is probably your disconnect) Belkar and Haley are surprised and freaked by the Fleet leaving. this is the next page and Haley is reassuring Belkar (and herself) that the others will come back for them. Since she is talking about a circumstance in which would require the group having actually abandoned them...Belkar has caught on to the fact that he isnt just missing something. That they really left.

Then Haley responds to Belkar freaking out by reminding him now to not die (shutting up)

The dialogue 'works' either way - that much is obvious. By intention or not, the ambiguous order doesn't affect the content.

At first glance, I read it as A. As many others have pointed out, no join between Haley's bubbles suggests that Belkar speaks in between them.

Over-scrutinising it into pointlessness, it's not been very neatly laid out (due to the necessity of showing the hobgoblins by the looks of it) making it the one slight mark on an otherwise impressive page layout.
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Though i agree it is not important it does have a KIND of relevance (unimportant relevance?)

obviously this is probably the first time the pair of them have addressed the situation, and since Belkar is surprised by her first comment we can assume that before this panel that it has only been in Haley's head that the consideration of whether or not the Order will come back for them (this is a direct link to the last page in which her self doubt eats at her one last time).

So she isnt really speaking to Belkar. She is talking out loud (probably mentally excusing herself from trying to reassure herself by thinking she is explaining "the plan" to Belkar) in order to reassure herself that "the plan" seems sound and they really weren't abandoned. So the importance is in showing How Leader Haley is trying to keep things together so that she doesn't break down into her self doubt. To her surprise the news (or confirmation of news rather) of what just happened shocks Belkar (thus showing how little she payed attention to him) thus causing his loud exclamation...bringing her back to reality and reminding her that there are more pressing matters than worring about if she will ever see her love again.