Ouch! That's a big job. Unfortunately, I haven't counted the number of endings per person, and it's not in character order but in production order in achievement menu, which can be confusing.
When I made it, I basically followed the sequence of three or four endings per three chapters, for reference！
Because the number is really more, I recommend looking at the guide to collect! (For example, search for a keyword like "B line/route") Hope it helps you!!