Help me understand PvE scoring

DarthDeVo

So I just finished up the Meet Rocket & Groot event. Despite grinding every node to 1 in every sub, I finished 17th, 438 points shy of 10th. I had a late start on the opening sub, so I'm not terribly surprised I didn't get T10. Now, this may have had more to do with the fact that Peggy was the placement reward. I know that's what I was gunning for. There was only 890 points between me in 17th place and first place, 453 between first and 10th (and 8 between 10th and 11th; sucks to be THAT guy).

Here's the part I don't understand though. I had a late start on the first sub, but was there when the second (48 hour) and third (24 hour) sub opened. After the first four clears I was in 5th place for the second sub and 3rd place for the third sub. Yet, I wasn't even able to finish T10 in those individual subs, despite playing each node down to one.

So please, help me understand: How can I go from 5th and 3rd place, play all the nodes down to one, and finish outside the top 10 for those individual subs?

The only thing I can think of is that sometimes I'll do a 5th clear with about four hours left so that I only have to do two final clears with about an hour left instead of three clears with about an hour and a half or an hour and fifteen minutes left. I don't know, maybe I'm starting my final grind too early and not getting enough points that way, but would it really make that much of a difference that it would boot me out of the top 10?

There's been a couple of times that I started my final grind with what I thought was enough time, but I ended up running out of time and missing out on grinding a node or two down to one. So I've decided I would rather start a little early and make sure I get the points rather than start late and miss out on points altogether. But would that really be such a spread that it negates the fact that I was 5th and 3rd after the initial clear? I know finishing earlier means my timers start earlier, so I should be getting more points for each of my subsequent clears. So how am I losing so much ground?