I don't like criticism so I'm going to plug my ears and sing the la la song
fixed
Hussie planned out the plot for homestuck before it even started.
Just because characters are introduced at different times, it doesnt make it bad.
In the Wizard of Oz, did the Tin Man, the Lion and the Scarecrow all jump out of a bush at the same time?
No. They didnt. Its better to introduce characters one at a time and get to know them better than introduce them all at once and overwhelm the reader
Most stories I've read have a main protagonist that is followed for the most part throughout the book/movie/whatever. Along the way they meet the rest of the cast.
For example, The Hitchhiker's Guide to the Galaxy mainly follows Arthur Dent and Ford Prefect. They are the first characters the reader is introduced to, and probably get the most screen time/page space. Later, the reader is introduced to the rest of the cast, Zaphod, Trillian, Marvin, and the rest. After that, there are parts where the narration gets away from Arthur and Ford to focus on say, Zaphod and Trillian. This is fine, because we know who the hell they are, and probably where they are as well.
That's been the formula for pretty much every book I've read. The only time it jumps between characters who haven't met is when they're all established at the beginning. My point is that randomly going to another setting and character where we have no clue what is happening is just disorienting. It's like reading some Harry Potter book and turning the page to find that there's an entire chapter from War and Peace just spliced in. Why couldn't you have introduced these people the way you introduced Marc?