Question about seemingly "random" Rancor reward placing when one person solos it?

I really don't think it's random. I joined at the beginning once, joined at the end the next time, both times DEAD LAST!!!! I've almost got Solo 7* and this is just crap. Maybe because I am new in the guild?

You can tell before any damage is done too, like this time I joined right before the damage started and I was already in last place at that point. The first time I joined at the beginning and was in 1st or 2nd, and then everyone that joined after me just kept knocking me further down the ladder so weird