Nah, you're good. Very informative answer~
I guess it's just difficult for me to think of that as separate from the composition of the rest of the comic. Like, if you have a colorist or a line artist, that makes sense to me, because those are completely separate tasks. You could do one today and one tomorrow.
But you can't just...not think about where the words are going to go when you draw a comic, especially when it comes to that sfx text, which is art in and of itself. Years of stupid mistakes have trained me to keep in mind how much text will have to fit into the panel before I even start sketching the characters...and I still struggle with it a lot of the time. I can't imagine delegating that task away to someone else...
I guess it's an issue that's more prevalent in manga than in Western comics, since the former are usually more text-heavy: in most manga I've read, the artists go out of their way to make space in the panels for text (sometimes a whole panel is basically just a speech bubble). Meanwhile, in Western comics...I mean, just look at the examples you gave. A half-inch to the left or right with the text wouldn't bother most of those panels. It's kind of enviable...