you mean they broke down the panels, but not the page? that’s… odd? that’s odd.
I’m gonna go ahead and say you should pretty much always outline for an artist the sum total of story data for each page. I know dudes writing Marvel style scripts that go way broad (Stan used to but that’s just not fair to your artist) and do things like
They eat breakfast. Ben and johnny argue. Reed and sue try to keep the peace when — wammo! dr. doom arives
They fight dr. doom
and so on which is just kinda bullshit. that’s not writing, that’s advising.
so yeah. sounds to me like you’re on your way. i try not to “call shots” too often — meaning to specify camera angles and such, focusing rather on the narrative moment of importance and trust my artist to find the right image. i’ll never outwrite stuart immonen’s hand so why try? tell him the undrawable stuff or the raw physical stuff and watch him bring the abstract to life and to give the visceral an emotional weight. Does that make sense?
Anyway it sounds to me like you did it just as right as any other way. i think every writer has to find how they write their scripts, and they have to find how they write their scripts for their artist. these are two wildly different things. Alan Moore and Neil Gaiman are the best thing to happen to comics writing and the worst things to happen to comics writers because their styles of script writing, so legendary as to become apocryphal and for the longest time the only printed examples of comics scripts one could find, made generations of kids write terrible sub-Alan Moore and terrible sub-Neil Gaiman scripts. The lesson is, of course, don’t write like Alan Moore or Neil Gaiman; write until you figure out how to write like you.
The only way i’ve found to know how many pages a scene needs is to write until it’s right. That’s why i tend to start with lists, working like very loose outlines. it gives me a rough breakdown of the mission each page has in the greater whole but keeps things loose enough that i can reshuffle and rework quickly.
in other words: there’s no easy answer, and the only way to figure it out is to do it a zillion times, and then do it a zillion more. i had a major breakthrough when i stopped being precious about my notebook pages and just did lots of Wrong Outlines.
i’d also do ‘cover versions’ of books i liked — or, more informatively, of books i hated — where i’d take a finished comic, write a number 1-22 (usually) down one side of the page, and then sum up on each page what happens. i did that for, what, twenty, twenty-five comics out there in the world by writers i loved and hated, for books that were wild commercial successes and books i loved but aren’t connecting and learned all kinds of stuff. ultimately it becomes your instinct.